Professional Psychology: Research and Practice 2015, Vol. 46, No. 1, 46 –54 © 2013 American Psychological Association 0735-7028/15/$12.00 http://dx.doi.org/10.1037/a0031824 Clinical Work With Non-Accepting Parents of Sexual Minority Children: Addressing Causal and Controllability Attributions Maya S. Shpigel, Yael Belsky, and Gary M. Diamond This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly. Ben-Gurion University of the Negev Nonaccepting parents of sexual minority children typically attribute their child’s same-sex orientation to external causes (e.g., early childhood experiences, peer pressure) and perceive sexual orientation as mutable and under their child’s control. Using scientific findings to introduce the possibility that sexual orientation may be, at least to some degree, biologically influenced, not a matter of choice and not under the child’s control, can reduce blame and anger and elicit empathy among these parents. This article provides therapists with an abbreviated summary of the extant research findings on the association between biology and sexual orientation, and on the results of sexual orientation change efforts, written in easily accessible language of the type we use when working with nonaccepting parents. In addition, we discuss the clinical issues therapists must consider when deciding how and when to introduce such information. Finally, we present a case study to illustrate this therapeutic process. Keywords: gay, lesbian, causal attributions, parents great majority feel more comfortable with, and supportive of, their child’s minority sexual orientation with the passing of time (BenAri, 1995; Holtzen & Agresti, 1990; Robinson, Walter, & Skeen, 1989). Likewise, a number of surveys of sexual minority adolescents have found that, on average, parents’ level of acceptance, and the quality of adolescent-parent relationships, improved over time (Beals & Peplau, 2006; Cramer & Roach, 1988; Savin-Williams & Ream, 2003), though one study found no change (D’Augelli et al., 2010). A recent Internet survey of Israeli sexual minority adolescents found that approximately 40% of parents who were initially fully or almost fully rejecting became more accepting by one and one half years (on average) postdisclosure (Samarova, Shilo & Diamond, under review). Facilitating increased tolerance or acceptance among initially rejecting parents is of tremendous import. When parents remain rejecting, angry, blaming, and invalidating over time, it can undermine the very fabric of the attachment relationship, the adolescent’s or young adult’s self-esteem, and his or her emotional/ psychological well-being. Indeed, research shows that parental criticism, invalidation, rejection, and abuse increase sexual minority adolescents’ and young adults’ risk for depression and suicidal ideation (D’Augelli et al., 2005; Remafedi, Farrow, & Deisher, 1991; Ryan, Huebner, Diaz, & Sanchez, 2009). In contrast, parental support buffers against psychopathology (D’Augelli, 2003; Eisenberg & Resnick, 2006; Evans, Hawton, & Rodham, 2004; Needham & Austin, 2010; Ryan, Russell, Huebner, Diaz, & Sanchez, 2010). Not surprisingly, when asked directly, sexual minority adolescents explicitly express a desire for improved relationships with their parents (Diamond et al., 2011; Samorova et al., under review). For many parents stuck in nonaccepting stances, their blame, anger, and criticism rest, in part, on the belief that their child’s sexual orientation is: caused by situational/environment factors (as opposed to biological factors); subject to change (i.e., mutable); and under the control of their child (controllability; Bernstein, Parents react to their children’s disclosure of a lesbian, gay, or bisexual (LGB) orientation (i.e., “coming out”) in various ways. Whereas some respond with understanding, acceptance, love, and support, others initially react with shock, disbelief, anger, guilt, shame, hurt, and grief. Indeed, research findings suggest that upward of 50% of parents initially react with some degree of negativity, with a small minority exhibiting severe forms of rejection, threatening behavior, and, in extreme cases, physical violence and/or ejection from the home (D’Augelli et al., 2010; Heatherington & Lavner, 2008; Robinson, Walters & Skeen, 1989; SavinWilliams, 1998, 2001). Very religious parents are more likely to react with rejection (Heatherington & Lavner, 2008). Fortunately, many parents who initially react negatively become more accepting, or at least more tolerant, over time. For example, studies of parents participating in gay affirmative support groups (e.g., Parents and Friends of Lesbians and Gays) show that the This article was published Online First March 11, 2013. MAYA S. SHPIGEL has an MA in clinical psychology and is currently completing her PhD dissertation in the Department of Psychology, BenGurion University of the Negev, Israel. She investigates change mechanisms in family therapy, including change processes in family therapy for homosexual offspring and their parents. YAEL BELSKY received her MA in clinical psychology from the Department of Psychology, Ben-Gurion University of the Negev, Israel. Her research interests are family dynamics and family therapy. GARY M. DIAMOND received his PhD in counseling psychology from Temple University and completed his post-doctoral training in clinical psychology at the University of Pennsylvania School of Medicine. He is an associate professor in the Department of Psychology, Ben-Gurion University of the Negev, Israel. His research interests include the process and outcome of family-based treatments, emotional processing and lesbian, gay and bisexual issues in psychotherapy. CORRESPONDENCE CONCERNING THIS ARTICLE should be addressed to Gary M. Diamond, Department of Psychology, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, Israel. E-mail: gdiamond@bgu.ac.il 46 This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly. NON-ACCEPTING PARENTS 1990). These three dimensions are related but not identical. Typically, nonaccepting parents attribute the onset of their child’s same-sex orientation to environmental forces such as peer influence, fear of the opposite sex, an absent father, a smothering mother, the lure of the gay community, and so forth. They use “evidence” from the past (e.g., a close relationship with a member of the opposite sex) to “prove” that their child’s sexual orientation was once heterosexual, and cling to stories they have heard or read of people who supposedly changed their orientation via pastoral counseling, conversion therapy, or simple strong will. By believing that their child was once heterosexual, and that his or her same-sex orientation was caused by external events, these parents maintain the hope that with sufficient motivation, effort, and/or the correct intervention, their child will “revert” to being heterosexual and, thus, alleviate their (the parents’) fears, conflicts, embarrassment, shame, loss, and so forth. When their child does not change, these parents’ frustrations turn to anger. A number of studies have explored the association between causal and controllability attributions and attitudes to LGB orientation. In one analogue study asking 356 colleges students to imagine that they were the parents of a 16-year-old homosexual boy, findings showed that the more the child’s homosexuality was perceived as being under his control, the more fury, anger, hate, and shame emerged. Conversely, the less homosexuality was perceived as under the adolescent’s control, the more affection was demonstrated (Armesto & Weisman, 2001). In two studies conducted by Haslam and Levy (2006), employing a sample of 487 college students and a sample of 216 adults from the community, the authors found that tolerance of minority sexual orientation was associated with the belief that same-sex orientation is immutable, biologically based, and historically and cross-culturally universal. In a study of two nationally representative samples of adults, Haider-Markel and Joslyn (2008) found that perceiving homosexuality as controllable was associated with negative affect toward homosexuals and perceiving homosexuality as uncontrollable (e.g., biological, genetic in origin) was associated with positive affect toward homosexuals. In our clinical work with nonaccepting parents, we have found that introducing the possibility that their child’s same-sex orientation may not simply be a choice but is, rather, influenced by biology and immutable, can lead to a decrease in anger and an increase in empathy toward their child. In some cases, when parents realize that they may have been demanding something from their child that their child cannot provide (i.e., change their sexual orientation), the enormity of the tragedy sinks in and sadness and compassion emerge. For some, though not for all, this realization is momentous and signals the transition from denial and rejection to the beginning of the acceptance process. One strategy for introducing the possibility that their children cannot control their sexual orientation, and therefore are not culpable, is to provide parents with up-to-date, scientifically accurate, user friendly information regarding what is known about the link between biology and sexual orientation and about the immutability of same-sex orientation. A number of good, detailed reviews of research findings on these topics already exist (cf. Hill, Dawood & Puts, 2012; Jenkins, 2010). However, such reviews are not necessarily aimed for the consumption of the average parent. The primary purpose of this article to is to provide clinicians with an abbreviated, select summary of the most compelling and easily 47 understood findings on the link between biology and sexual orientation and on efforts to change sexual orientation. The summary is written in accessible language, of the type we typically use when working with nonaccepting parents. For those clinicians and parents wanting more detailed information about biology and sexual orientation, we have included a list of relevant references (see Appendix). In addition, we discuss the clinical issues therapists must consider when deciding how and when to introduce such information. Finally, we present a case study to illustrate this therapeutic process. Clinically Oriented Summary of Research on Biology and Sexual Orientation and on Sexual Orientation Change Efforts Biology refers to a wide range of factors and processes, including genetic makeup, organ structure, enzyme production, dendritic growth, and exposure to prenatal hormones, to name a few. Below, we review findings from the areas of behavioral genetics, prenatal development, and brain morphology. Behavioral Genetics Many parents wonder whether their child’s sexual orientation is determined by genes. Indeed, genetics have been found to influence many of our physical traits, as well as our psychological functioning. Researchers typically describe the contribution of genes in terms of heritability rate—the degree to which individual differences in the population are explained by our genes. One way to estimate heritability rates is through family and twin studies. Fifty years of such research have generated compelling and consistent evidence that lesbians and gay men are more likely than heterosexual men and women to have gay siblings. For example, in one study researchers found that approximately one-quarter of gay men’s brothers also reported being gay—roughly four times the rate found among brothers of heterosexual men (Pillard & Weinrich, 1986). Moreover, twin studies consistently show that identical twins, who by definition share the same genetic make-ups, are 2 to 4 times more likely to both be gay than nonidentical twins, who share only half of their genetic makeup. In one recent largescale twin study conducted in Sweden, genetics accounted for up to 39% of the variation in sexual orientation identity among males and up to 19% among women (Långström, Rahman, Carlstrom, & Lichtenstein, 2010). In another recent large-scale study conducted in Finland, the heritability rate was 45% and 50% for women and men, respectively (Alanko et al., 2010). In summary, genetics appear to play an important role in the development of sexual orientation. While their influence is less than that found in traits such as height and eye color (with heritability rates of approximately 80%) (Bräuer & Chopra, 1978; Magarey, Boulton, Chatterton, Schultz, & Nordin, 1999), it is substantially higher than that found in phenomena such as major depression (with a heritability rate of approximately 34%; Nes et al., 2012). Moreover, the closer the genetic relation, the greater the likelihood that two related individuals will be concordant for sexual orientation However, despite the overwhelming evidence suggesting that genes are to some degree implicated in the development of sexual orientation, there is still no reliable evidence indicating exactly which genes are implicated (Hill, Dawood & Puts, 2012; Jenkins, 2010). 48 SHPIGEL, BELSKY, AND DIAMOND This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly. Prenatal Development There is some research suggesting that levels of certain hormones (e.g., testosterone, estrogen), released during pregnancy, may influence the development of sexual orientation. One approach to investigating the link between such hormones and sexual orientation is by examining finger length, because these same hormones are thought to influence finger growth in utero. Perhaps the most researched phenomenon relates to the relative lengths of the second and fourth fingers. A number of studies have found that the ratio of the second finger to fourth finger (2D:4D) is lower in gay males than it is in heterosexual males. A recent systematic review of the research on this topic, however, concluded that although there seems to be evidence that 2D:4D differs between lesbian and heterosexual women, there does not seem to be a difference between gay and heterosexual men (Grimbos, Dawood, Burriss, Zucker, & Puts, 2010; Rahman, & Wilson, 2003). Another biological marker studied has been “handedness.” Handedness is thought to be the result of prenatal development of the brain. A meta-analysis (Lalumière, Blanchard, & Zucker, 2000) of all studies up until the year 2000 found that gay men were a third more likely than heterosexual men, and lesbians were almost twice as likely as heterosexual women, to be left-handed or ambidextrous. Findings from these two lines of research provide some support for the hypothesis that prenatal hormone levels may partially determine or influence sexual orientation development (Hill, Dawood & Puts, 2012). Brain Morphology Although the brains of homosexual and heterosexual men, and lesbian and heterosexual females, are for the most part similar, a number of studies have found differences between individuals with same-sex versus other-sex orientations regarding specific brain structures. One such structure is the hypothalamus, which is implicated in the generation of male typical sexual behavior (LeVay, 1991). Studies have found that the size and density of neurons in the hypothalamus differ among homosexual men versus heterosexual men (Byne et al., 2001; LeVay, 1991; Swaab & Hoffman, 1990). Another such structure is the anterior commissure (AC)—a bundle of nerve fibers connecting the two cerebral hemispheres. One study found that homosexual males evidenced the largest anterior commissure, followed by heterosexual women and, in turn, heterosexual men (Allen & Gorski, 1993), though a later study found no between-gender or between-orientation differences in the size of the AC (Lasco, Jordan, Edgar, Petito, & Byne, 2002). Researchers have also found that the corpus callosum, the primary band of neural fibers connecting the left and right cerebral hemispheres, is larger in homosexual men than in heterosexual men (Witelson et al., 2008). In terms of the relative size of the two cerebral hemispheres, there is evidence that whereas heterosexual males and homosexual women have slightly larger right hemispheres than left hemispheres, the two hemispheres of homosexual males and heterosexual women are symmetrical (Savic & Lindstrom, 2008). In addition, the amygdala—that brain structure implicated in the processing of emotional memories—appears to function differently according to gender and sexual orientation. More specifically, whereas the left amygdala showed greater connectivity to other brain structures among heterosexual women and homosexual men, the right amygdala showed greater connectivity among heterosexual men and homosexual women (Savic & Lindstrom, 2008). Finally, there are findings suggesting that certain basic cognitive processes, such as spatial memory, mental rotation, verbal fluency, and recognition of facial expressions of emotion, are different among homosexual men in comparison with heterosexual men. In summary, a substantial body of research suggests that there are brain differences between lesbian or gay individuals in comparison with heterosexual individuals, though much more research is required to understand the nature of the association between brain structure and sexual orientation (Hill, Dawood & Puts, 2012; Jenkins, 2010). Environment/Life Experiences In the past, some have suggested that environmental factors, such as early parent– child interactions and sexual experiences, could cause an individual to become homosexual or lesbian (Friedman & Downey, 2008). To date, however, there is no methodologically sound research supporting such theories (Frankowski, 2004). In fact, there is quite a lot of research showing that parental gender, gender behavior, and attitudes toward homosexuality most likely do not influence children’s sexual orientation. For example, studies show that children raised by homosexual or lesbian couples are not more likely to be homosexuals or lesbians themselves (Allen & Burrell, 1996; Bailey, Bobrow, Wolfe, & Mikach, 1995; Gartrell, Bos, & Goldberg, 2011; Golombok & Tasker, 1996; Stacey & Biblarz, 2001), though in one recent study adolescent females raised by lesbian mothers were more likely to have had same-sex contact and define themselves as bisexual (Gartrell, Bos, & Goldberg, 2011). With regard to sexual experiences, research shows that lesbian adolescents were as likely as heterosexual female adolescents to have experienced intercourse, suggesting that they were not lesbian because they had not experienced heterosexual sex (Saewyc, Bearinger, Blum & Resnick, 1999). Sexual Orientation Change Efforts (SOCE), Including Conversion Therapy What we tell parents about SOCE is derived, primarily, from the report by the American Psychological Association Task Force on Appropriate Therapeutic Responses to Sexual Orientation (APA, 2009). We explain that there is a very small amount of rigorous research on sexual orientation change efforts. A summary of the findings that are available suggests that enduring change to an individual’s sexual orientation is uncommon and that a very small minority of people in these studies showed any evidence of reduced same-sex sexual attraction. Likewise, evidence that SOCE increased sexual behavior with the opposite sex is rare. Counseling and psychotherapy approaches designed to change sexual orientation have not been rigorously evaluated, and there is no basis for concluding that they are effective. Not only is there no evidence that SOCE are effective, there is evidence to indicate that individuals experience harm from such efforts. For example, in a study of 202 individuals who had undergone sexual orientation change efforts, including aversion conditioning, psychotherapy, and religious counseling, two thirds described the interventions they received as “harmful only” (38%) or “both harmful and helpful” (28%) (Shidlo & Schroeder, 2002). Participants of sexual orientation change efforts describe negative social, emotional, and spiritual consequences as a result of their experience, including anger, anxiety, confusion, depression, grief, guilt, hopelessness, deterioration This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly. NON-ACCEPTING PARENTS of relationships with family, loss of social support, loss of faith, poor self-image, social isolation, intimacy difficulties, intrusive imagery, suicidal ideation, self-hatred, and sexual dysfunction. A minority of participants did report experiencing benefits, such as relief, happiness, improved relationship with God, and perceived improvement in mental health status, though some described experiencing these benefits initially, only to later experience or acknowledge the negative effects (Morrow & Beckstead, 2004; Shidlo & Schroeder, 2002). It is important to note, however, that we have no way of knowing to what degree these samples are representative of the entire population of individuals undergoing SOCE. Nevertheless, because of the lack of support for SOCE, and because of their potential to cause harm, the American Psychological Association suggests that mental health professionals avoid telling clients that they can change their sexual orientation through therapy or other treatment. The APA also suggests that therapists advise clients to avoid sexual orientation change efforts that portray homosexuality as pathological and, instead, to seek treatment, social support, and educational services that provide accurate information about sexual orientation, increase family and school support, and reduce rejection of sexual minority youth (APA, 2009). The American Psychiatric Association adopted a similar resolution in 2000, stating that the organization opposes therapeutic techniques intended to change an individual’s sexual orientation from homosexual to heterosexual. The Board of Trustees went on to state that there is no evidence that so-called reparative therapies have any efficacy (APA, 2000). Recently, the California State Assembly passed a bill making it illegal for mental health practitioners to administer treatments intended to change the sexual orientation, romantic attractions, or gender expression of children and adolescents under the age of 18. Clinical Issues Introducing the possibility that sexual orientation may be innate and/or immutable is a powerful intervention that must be skillfully and sensitively employed. If the possibility is introduced prematurely, parents may experience the therapist as allied with their child and as lacking understanding and empathy for their own suffering and anger. Along the same lines, if the possibility is introduced too forcefully, as an unequivocal fact, parents may feel coerced or railroaded into adopting a position they are not yet ready or able to fully consider. Both of these negative processes can undermine the therapeutic alliance. For that reason, introducing the possibility that sexual orientation may not be a choice, and may not be controllable, needs to be done gradually, nonpassionately, and in a manner that accurately reflects the current state of the science. Only after parents feel that the therapist understands and empathizes with their own distress, and that they (they parents) have the freedom and time to weigh all of the evidence, will they be open to considering alternative causal and controllability attributions. When speaking with parents, we always begin by pointing out that, at this point in time, nobody knows for sure exactly why an individual expresses a same-sex orientation, though we make it clear that there is no credible evidence that sexual orientation is attributable, even in part, to social factors. To date, researchers have yet to identify specific genes, hormones, or other physiological factors that can be said, with certainty, to determine or influence the development of sexual orientation. Nevertheless, there are findings from a substantial amount of studies across a wide range of domains that strongly suggest that biology plays a role in the development of sexual orientation. 49 Depending on the needs and capacities of the parents, the findings listed above can be presented in less or more detail. For some parents, it is enough to hear that there is some research suggesting a link between genes and sexual orientation. Others may want to know how much variance genes account for, how many studies have been conducted, and whether the findings are the same for men and women. Also, the breadth of information provided at a given moment varies. In some cases, parents make a general request for information on the association between biology and sexual orientation and we respond with a five- to 10-minute psycho-educational summary of the data appearing above. In other instances, we introduce brief bits of data as part of our responses to parents’ specific questions or concerns, as they arise. For example, some parents may have questions about the potential benefits of conversion therapy at the start of therapy, and only later, after recognizing that their child is not likely to change their sexual orientation, then have other questions about the role of genetics in the development of same-sex orientation. In all cases we are careful to monitor parents’ reactions as we present them with the data. When parents respond with openness, curiosity, and in an engaged manner, we proceed to offer additional information and explore the impact the information is having on the parent and on his or her attitudes/feelings toward their child. On the other hand, when parents respond defensively or become overwhelmed, we take a step back, empathize with their distress about how hard the process is for them, and offer support. Composite Case Example Yaacov (age 64) and Rivka (age 60) immigrated to Israel from Yemen as children in the 1950s. Rivka works as clerk in a government office and Yaacov as a foreman in a factory. Although they do not identify themselves as being religious, both come from traditional families. They are parents of 6 children ranging in age from 20 to 52. Yonni (age 25), their second to youngest son, came out to them as gay approximately one year ago. They agreed to participate in our family therapy program after Yonni, with our encouragement, wrote them a letter explaining how much he cared about them, how important his relationship with them was, and how much he wanted them to join him in family treatment. During the first session, both Rivka and Yaacov described the shock they experienced when Yonni disclosed his sexual orientation to them. Rivka: “I thought I didn’t hear him correctly. I had to ask him to repeat what he said—it was like . . . I couldn’t think or comprehend for . . . I don’t know how many minutes passed. My heart dropped. He is the last person in the world I would have thought would be like that— he was always so manly, liked sports—the girls were all over him.” Yaacov: “Yes. That’s true. It was like thunder on a clear day. I still don’t understand. I have asked myself a million times—where did I go wrong—was I not involved enough with him? Was I too soft with him?” Therapist: “I don’t think many parents are fully prepared to hear their son say, ‘Mom, Dad . . . I am gay.’ Especially when it comes completely unexpectedly.” After hearing more about their shock, anger, shame, and fears, the therapist returned to Yaacov’s questions about his possible role in the development of Yonni’s sexual orientation. This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly. 50 SHPIGEL, BELSKY, AND DIAMOND Therapist: “You know, Yaacov, I heard you saying that you wonder whether something you did or didn’t do, something about your parenting, the way you treated Yonni, is responsible for his being gay. What exactly do you think you should have done differently?” Yaacov: “We wanted him to come and speak with our Rabbi—the Rabbi said he was willing to talk to Yonni. I thought that maybe if I could get him more involved in the synagogue, in the morning prayer group, perhaps that might make a difference.” Yaacov: “I don’t know . . . maybe I should have provided more of a masculine role model . . . played more sports with him.” Rivka: “We heard from others that in some cases, it is possible to get the person back on the ‘right’ track. I even heard one man speak about how he had overcome his homosexuality and was now living a life just like everybody else—married, with children.” Therapist: “I hear what you are saying. For a lot of parents, that is a natural instinct—to question or blame themselves. We can talk more about it later if you would like, but I just want you to know right now that there is no compelling evidence of any kind suggesting a connection between parenting and children’s sexual orientation. There have been lots of theories about absent fathers, overinvolved mothers, and so forth but really no data supporting these contentions. Even among families with two lesbian parents, boys are not more likely to grow up gay.” Later in the session, Rivka returns to the question of how her son came to be gay and the implications. Rivka: “I don’t understand. What would make him choose that path? Doesn’t he realize that his life is going to be hell? That our life is going to be hell?” Therapist: “I hear how hard this is for you. It also sounds like you are worried about how hard it is going to be for Yonni—that you are pained thinking about what he will be up against . . . .” After spending some time exploring and acknowledging Rivka’s and Yaacov’s fears about the future, the challenges both they and Yonni will face, and introducing the possibility of an alternative narrative—an alternative future that is not dominated by isolation, shame and loss but rather connection and meaning—the therapist turns to the question of causality. Therapist: “Rivka, a few minutes ago you mentioned the word ‘choice’—that you couldn’t understand why Yonni ‘chose’ to be homosexual. I was wondering whether you had considered that maybe Yonni didn’t ‘choose’ to be gay, but was perhaps born that way?” Rivka: “We have heard others say that. What can I say . . . ” Yaacov: “You know, we have relatives—Rivka’s cousin. They have two daughters who are both lesbian.” Rivka: “I feel terrible for them. It was one catastrophe after the other for them.” Therapist: “You know, there is quite a bit of research suggesting that sexual orientation, at least in part, may be related to genetics or other biological processes and may not be much of a choice, if at all. For example, there are some findings suggesting that the amount of certain hormones released during pregnancy may impact upon sexual orientation.” Yaacov: “Yes, on one hand it makes sense—I can’t think of anything we did or that was out of the ordinary while he was growing up.” Finally, near the end of the session, Rivka lamented about wishing Yonni would change, wishing that he would at least try to live a “normative” lifestyle, find a woman, start a family. Rivka: “I just wish he would try . . . to see if he could change himself back to normal.” Therapist: “I can certainly understand why you would wish that, somehow, all of this could be different and that Yonni would somehow transform into being heterosexual, the way you always expected. The idea of having a gay son, particularly in the beginning, is hard and scary, and magically ‘changing’ him into a heterosexual would somehow eliminate all of those problems. You know, many have explored whether it is possible to change one’s sexual orientation. The fact is that reports of people changing their sexual orientation, particularly when they identify as exclusively homosexual, are very rare and generally unvalidated. There have been numerous surveys on people’s experience participating in all sorts of sexual orientation change efforts, including psychotherapy, pastoral counseling. Overall, there is no credible evidence that such efforts change sexual orientation, though there has been very little rigorous research examining this question. For people who report a more fluid or bisexual orientation, fluctuations in self-defined sexual orientation are more common. However, in large surveys, a very small percentage of respondents reporting that they were gay and went to therapy to change (either because of family or societal pressure or because of internalized discomfort) reported that they had indeed changed. Just as importantly, the great majority of people surveyed who underwent sexual orientation change efforts reported feeling harmed by the effort, including experiencing increased guilt, self-contempt, hopelessness, and suicidal ideation, among other things.” Discussion The primary purpose of this article is to provide therapists working with nonaccepting parents of LGB individuals with a user-friendly summary of research findings that they can use to introduce, or better establish, the possibility that sexual orientation is, at least partially, attributable to biology and not a choice, and that efforts to change sexual orientation, particularly coercive efforts, are likely to be unsuccessful and detrimental. Introducing the possibility that sexual orientation may be biologically determined and immutable is a potentially critical change intervention for nonaccepting parents and, in turn, their relationship with their child. As mentioned above, there is a strong link between causal and controllability attributions and attitudes toward homosexuality. Nonaccepting parents who tenaciously hold onto the belief that their child has “chosen” to be gay, and can therefore choose to become heterosexual, are less likely to be willing to work toward acceptance or even tolerance. On the other hand, when such parents recognize that there is even a small possibility that their child is not responsible for their same-sex orientation and, in fact, has suffered in his or her struggle to come to peace with his or her sexual orientation, parents are likely to become more empathic and supportive and the process of shared acceptance can begin. Although the potential usefulness of introducing the idea that biological factors influence sexual orientation is clear, a number of caveats are warranted. First, for some religious families, the contention that homosexuality may be even partly attributable to biological factors runs counter to their interpretation of the Bible and, therefore, holds little traction. They argue that the Bible is unequivocal about homosexuality being a sin and that God would not have created This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly. NON-ACCEPTING PARENTS individuals who were innately gay. Indeed, holding orthodox or fundamental religious beliefs is one of the more robust predictors of parental nonacceptance (Heatherington & Lavner, 2008; Newman & Muzzonigro, 1993; Schope, 2002). To resolve or circumvent this conflict, some gay friendly clergy have reinterpreted the relevant biblical verses, emphasized the distinction between sexual orientation (urges) and actual sexual behavior, highlighted fundamental JudeoChristian values such as acceptance and the importance of not judging others, focused on the greater good of preserving the parent– child relationship, and reminded parents that no one can fully understand God’s intentions and plans (Rodriguez & Ouellette, 2000). With that said, orthodox religious parents are likely to have a difficult time integrating biological causal attributions for homosexuality with their religious beliefs, and introducing them to such research findings may be ineffective, inappropriate, or even counterproductive in some cases. With this population, therapists need to be particularly cautious and carefully monitor parents’ reactions to the information presented on a moment-to-moment basis. Second, invoking biological, essentialist causal attributions may be more challenging with parents of nonheterosexual females, and in particular bisexual females, than with parents of homosexual males. Research suggests that sexual orientation is generally more clearly defined among men, with most men identifying as either homosexual or heterosexual, and only a few identifying as bisexual (Hammack, 2005). Moreover, men less often report change in their sexual orientation over time (Kinnish, Strassberg & Turner, 2005). These two related findings are consistent with an essentialist approach: that one’s physiology is central in determining sexual orientation. In contrast, female sexual orientation appears to be more varied, with women reporting a wider range of self-identifications including many who self-identify as bisexual (Hammack, 2005). Moreover, research suggests that female sexual orientation is more fluid than that of men (Diamond, 2000, 2003; Kinnish et al., 2005; Savin-Williams & Diamond, 2000; Savin-Williams & Ream, 2007). Such fluidity presents a challenge to biological, essentialist explanations and, in turn, may complicate the acceptance process. Indeed, there are research findings that indicate that fathers have particular difficulty accepting their lesbian daughters (Heatherington & Lavner, 2008). Also, a recent study of Israeli sexual minority adolescents suggests that parents had the most difficulty accepting their bisexual daughters (Samarova, Shilo, & Diamond, under review). Third, although a biological causal model is likely to reduce parents’ blame and anger toward their child, it has the potential to increase parents’ own guilt, and in some cases, even lead one parent to blame the other. However, it is worth noting (and perhaps reminding parents) that individuals (including themselves) are not responsible for their own genetic makeup or biological functioning. Moreover, biological causal models alleviate what is generally a greater concern among parents: that they may have somehow actively, albeit unwittingly, influenced their child’s sexual orientation through their parenting style/choices. A fourth consideration when invoking biological causal models is that they can potentially be used to pathologize sexual minority individuals. He is gay because he has a disease, a genetic deformity, and so forth. Above and beyond the insult inherent to pathologizing what is in fact a normal variation of human sexuality, such pathologizing can quickly lead to stigmatization and, subsequently, to discrimination. Moreover, many fear that pathologizing homosexuality can lead to, or promote, 51 eugenic ideas: provide a rational or justification for biological interventions to eliminate or alter same-sex orientation. Yet another concern is that the very use of terms such as homosexual, lesbian, bisexual, and heterosexual is offensive to certain individuals. For many sexual minority individuals aligned with a “queer” stance, such labels are experienced as artificial, restrictive, and essentialist in nature—vehicles for defining what is normal, permissible, and not. Such individuals are more likely to view gender, gender behavior, sexual orientation and behavior, and selfidentification as varied, fluid, and as socially, historically, culturally, and politically constructed (Spargo, 1999). They are likely to spurn both the use of labels and biological causal theories. In such circumstances, the adolescent or adult child him/herself might be averse to the idea of the therapist invoking biological models when explaining their sexual orientation to their parents. An additional concern is that, for some individuals, any discussion of cause is perceived as “missing the point.” Such individuals take the position that it doesn’t matter “why” somebody is gay. Instead, parents should be concerned with accepting and being proud of their children, regardless of their sexual identity and inclinations. To this we can only respond with an emphatic, resounding, “Yes. We agree!” However, for many parents, being affirming, or even just least tolerant, is the end result of a process, not the beginning. Nonaccepting parents are typically organized by their shame, fears, frustrations, and anger. Introducing a frame in which no one is to blame can serve to neutralize or temper such feelings long enough for parents to become more reflective and allow other feelings and thoughts to arise, such as their love for their child, concern for his or her emotional welfare, and the importance of their relationships with him/her. For such parents, introducing the possibility of biological causes is an instrumental, strategic intervention useful early in the therapy process. In a study of parents participating in a gay empowerment parent support group, Fields (2001) found that most newcomers to the group experienced the biological argument as comforting. However, with time, most members eventually rejected the debate on the causes of homosexuality and, instead, focused more on acceptance, affirmation, and advocacy. Indeed, one of the participants reported that while she initially found the biological argument comforting, after becoming more comfortable with her son’s gay identity she now resented discussions of biological causal models. Most interestingly, long-term members of the group reported that they themselves were strategic in their use of biological causal models when speaking with new members. They invoked research supporting such models when addressing new members who were still consumed by their search for reasons why their child was gay and who were concerned about the possibility that they had contributed to their child’s same-sex orientation through their parenting. For many parents new to the group, “assigning responsibility for homosexuality to natural forces over which they had no control allowed them to avoid embracing lesbian and gay sexuality while still accepting their daughters and sons” (Fields, 2001, p. 174). Finally, some might take the position that working with nonaccepting parents is a useless endeavor or, worse, unethical—that it invalidates children’s (young or adult) legitimate expectations that their parents fully accept and prize them for who they are, in their entirety, including their sexuality. They take an all-or-nothing position: Until parents are able to come to full acceptance, any contact with that parent is toxic. Unquestionably, ongoing contact with nonaccepting parents is potentially harmful for their sexual minority offspring. For parents who are particularly critical and rejecting, even intermittent SHPIGEL, BELSKY, AND DIAMOND This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly. 52 contact can be destructive. For that reason, as therapists, we place a premium on helping adolescents and young adults protect themselves from excessive criticism, humiliation, or abuse. With that said, relationships with parents continue to be important to most individuals throughout their lives. Consequently, we work individually with nonaccepting parents, sometimes for months, in an effort to help them articulate, differentiate between, and overcome their fears, anger, shame, and loss. We help them to focus more on their love for their child, the welfare of their child, and their deep-seated, instinctual desire to maintain a relationship with their child. When parents’ fear, anger, and shame sufficiently subside, and their desire to work on their relationship comes to the fore, we initiate conjoint sessions focused on increasing safety and acceptance in the relationship and deepening the attachment bond. In those cases in which, despite our best efforts, parents rigidly hold onto their anger and demands that their child “change,” we are left to grieve, together with the child. However, in light of the research demonstrating the protective role of parental acceptance and support, and in light of the deep seated need we all carry to feel that our parents our proud of us, accept us, and love us, articulating and testing interventions that can potentially facilitate the acceptance process among nonaccepting parents is warranted. Whereas the focus of this article is on conducting psychotherapy with families with nonaccepting parents, the potential utility of introducing parents to research on biology and sexual orientation extends beyond the clinic to other settings. For example, many schools and community centers offer parenting classes for parents of young children and adolescents. In the context of such classes, introducing same-sex orientation as a common phenomenon influenced, to some degree, by biology may help moderate the reactions of parents whose children subsequently “come out” (i.e., primary prevention). Likewise, professionals can present such information to parents concerned about what they perceive as their child’s atypical gender behavior (i.e., secondary prevention). Finally, the more such findings are profiled in the mass media, the more likely it is that the general public will adopt more tolerant, accepting attitudes to sexual minority individuals (Altemeyer, 2002; Haslam & Levy, 2012). References Alanko, K., Santtila, P., Harlaar, N., Witting, K., Varjonen, M., Jern, P., Johansson, A., von der Pahlen, B., & Sandnabba, N. K. (2010). Common genetic effects of gender atypical behavior in childhood and sexual orientation in adulthood: A study of Finnish twins. Archives of Sexual Behavior, 39, 81–92. Allen, L. S., & Gorski, R. A. (1992). 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A. (2010). Sexual orientation and the second to fourth finger length ratio: A metaanalysis in men and women. Behavioral Neuroscience, 124, 278 –287. Haider-Markel, D. P., & Joslyn, M. R. (2008). Beliefs about the origins of homosexuality and support for gay rights: An empirical test of attribution theory. Public Opinion Quarterly, 72, 291–310. Hammack, P. L. (2005). The life course development of human sexual orientation: An integrative paradigm. Human Development, 48, 267–290. Haslam, N., & Levy, S. R. (2006). Essentialist beliefs about homosexuality: Structure and implications for prejudice. Personality and Social Psychology Bulletin, 32, 471– 485. Heatherington, L., & Lavner, J. A. (2008). Coming to terms with coming out: Review and recommendations for family systems-focused research. Journal of Family Psychology, 22, 329 –343. Hill, A. K., Dawood, K., & Puts, D. A. (2012). Biological foundations of sexual orientation. C. J. Patterson & A. R. D’Augelli, (Eds.), Handbook of psychology and sexual orientation. New York, NY: Oxford University Press. Holtzen, D. W., & Agresti, A. A. (1990). Parental responses to gay and lesbian children: Differences in homophobia, self-esteem, and sex-role stereotyping. Journal of Social and Clinical Psychology, 9, 390 –399. Jenkins, W. J. (2010). Can anyone tell me why I’m gay? What research suggests regarding the origins of sexual orientation. North American Journal of Psychology, 12, 279 –296. Kinnish, K. K., Strassberg, D. S., & Turner, C. W. (2005). Sex differences in the flexibility of sexual orientation: A multidimensional retrospective assessment. Archives of Sexual Behavior, 34, 173–183. Lalumière, M. L., Blanchard, R., & Zucker, K. J. (2000). Sexual orientation and handedness in men and women: A meta-analysis. Psychological Bulletin, 126, 575–592. Långström, N., Rahman, Q., Carlström, E., & Lichtenstein, P. (2010). 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Sexual orientation, parental support, and health during the transition to young adulthood. Journal of Youth and Adolescence, 39, 1189 –1198. Nes, R. B., Czajkowski, N. O., Røysamb, E., Orstavik, R. E., Tambs, K., Reichborn-Kjennerud, T. (2012). Major depression and life satisfaction: A population-based twin study. Journal of Affective Disorders, 28. Newman, B. S., & Muzzonigro, P. G. (1993). The effects of traditional family values on the coming out process of gay male adolescents. Adolescence, 28, 213–227. Pillard, R. C., & Weinrich, J. D. (1986). Evidence of familial nature of male homosexuality. Archives of General Psychiatry, 43, 808 – 812. Rahman, Q., & Wilson, G. D. (2003). Sexual orientation and the 2nd to 4th finger length ratio: Evidence for organising effects of sex hormones or developmental instability? Psychoneuroendocrinology, 28, 288 –303. 53 Remafedi, G., Farrow, J. A., & Deisher, R. W. (1991). Risk factors for attempted suicide in gay and bisexual youth. L. D. Garnets & D. C. Kimmel (Eds.), Psychological perspectives on lesbian and gay male experiences. Between men—Between women: Lesbian and gay studies (pp. 486 – 499). New York, NY: Columbia University Press. Robinson, B. E., Walters, L. H., & Skeen, P. (1989). Response of parents to learning that their child is homosexual and concern over AIDS: A national study. Journal of Homosexuality, 18, 59 – 80. Rodriguez, E. M., & Ouellette, S. (2000). Gay and lesbian Christians: Homosexual and religious identity integration in the members and participants of a gay-positive church. Journal for the Scientific Study of Religion, 39, 333–347. Ryan, C., Huebner, D., Diaz, R. M., & Sanchez, J. (2009). Family rejection as a predictor of negative health outcomes in white and Latino lesbian, gay, and bisexual young adults. Pediatrics, 123, 346 –352. Ryan, C., Russell, S. T., Huebner, D., Diaz, R. M., & Sanchez, J. (2010). Family acceptance in adolescence and the health of LGB young adults. Journal of Child and Adolescent Psychiatric Nursing, 23, 205–213. Saewyc, E. M., Bearinger, L. H., Blum, R. W., & Resnick, M. D. (1999). Sexual intercourse, abuse and pregnancy among adolescent women: Does sexual orientation make a difference? Family Planning Perspectives, 31, 127–131. Samarova, V., Shilo, G. & Diamond, G. M. (under review). Changes over time in parents’ acceptance of their Israeli sexual minority adolescents. Savic, I., & Lindstrom, P. (2008). PET and MRI show differences in cerebral asymmetry and functional connectivity between homo- and heterosexual subjects. PNAS, 105, 9403–9408. Savin-Williams, R. C. (1998). The disclosure to families of same-sex attractions by lesbian, gay, and bisexual youths. Journal of Research on Adolescence, 8, 49 – 68. Savin-Williams, R. C. (2001). A critique of research on sexual-minority youths. Journal of Adolescence, 24, 5–13. Savin-Williams, R. C., & Diamond, L. M. (2000). Sexual identity trajectories among sexual-minority youths: Gender comparisons. Archives of Sexual Behavior, 29, 607– 627. Savin-Williams, R. C., & Ream, G. L. (2007). Prevalence and stability of sexual orientation components during adolescence and young adulthood. Archives of Sexual Behavior, 36, 385–394. Savin-Williams, R. C., & Ream, G. L. (2003). Sex variations in the disclosure to parents of same-sex attractions. Journal of Family Psychology, 17, 429 – 438. Schope, R. D. (2002). The decision to tell: Factors influencing the disclosure of sexual orientation by gay men. Journal of Gay and Lesbian Social Services, 14, 1–22. Shidlo, A., & Schroeder, M. (2002). Changing sexual orientation: A consumers’ report. Professional Psychology: Research and Practice, 33, 249 –259. Spargo, T. (1999). Foucault and queer theory. New York, NY: Totem Books. Stacey, J., & Biblarz, T. J. (2001). (How) does the sexual orientation of parents matter? American Sociological Review, 66, 159 –183. Swaab, D. F., & Hofman, M. A. (1990). An enlarged suprachiasmatic nucleus in homosexual men. Brain Research, 537, 141–148. Witelson, S. F., Kigar, D. L., Scamvougeras, A., Kideckel, D. M., Buck, B., Stanchev, P. L., Bronskill, M., & Black, S. (2008). Corpus callosum anatomy in right-handed homosexual and heterosexual men. Archives of Sexual Behavior, 37, 857– 863. (Appendix follows) 54 SHPIGEL, BELSKY, AND DIAMOND Appendix This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly. Select Resources for Information on Biology and Sexual Orientation LeVay, S. (2009). The biology of sexual orientation. http://www .simonlevay.com/the-biology-of-sexual-orientation LeVay, S., & Hamer D. H (1994). Evidence for a biological influence in male homosexuality. Scientific American, 270, 44 – 49. Hill, A.K., Dawood, K., & Puts, D.A. (2012). Biological foundations of sexual orientation. C. J. Patterson & A. R. D’Augelli, (Eds.), Handbook of psychology and sexual orientation. New York, NY: Oxford University Press. Jenkins, W.J. (2010). Can anyone tell me why I’m gay? What research suggests regarding the origins of sexual orientation. North American Journal of Psychology, 12, 279 –296. flushSavic, I., Garcia-Falgueras A., & Swaab, D.F. (2010). Sexual differentiation of the human brain in relation to gender identity and sexual orientation. Progress in Brain Research, 186, 41– 62. Swaab, D. F., Gooren, L. J., & Hofman, M. A. (1995). Brain research, gender and sexual orientation. Journal of Homosexuality, 28, 283–301. flushSwaab, D. F. (2008). Sexual orientation and its basis in brain structure and function. Proceedings of the National Academy of Sciences of the United States of America, 105, 10273– 10274. Received August 6, 2012 Revision received December 27, 2012 Accepted January 7, 2013 䡲 Call for Papers: Experimental and Clinical Psychopharmacology Special Issue for August 2015 on: Sex Differences in Drug Abuse: Etiology and Implications for Prevention and Treatment The goal of this special issue is to broadly highlight how males and females differ in their risks for substance abuse, in their responses to treatments, and in their relapse to substance use after a period of abstinence. Relevant approaches include (but are not limited to) laboratory behavioral, social behavior and environmental context, brain development and function, and the role of genetics, hormones and neuropeptides. Both animal and human methods are appropriate for this issue. Collaborative manuscripts that bridge animal and human findings are especially valued. This special issue is intended to showcase the importance of studying sex differences in drug abuse and how this research might lead to more tailored approaches for prevention and treatment. Laboratories engaged in research in this area may submit review articles or primary research reports to Experimental and Clinical Psychopharmacology to be considered for inclusion in this special issue. Manuscripts should be submitted as usual through the APA Online Submission Portal (www.apa.org/pubs/journals/pha/), and the cover letter should indicate that the authors wish the manuscript to be considered for publication in the special issue on Sex Differences in Drug Abuse. All submissions will undergo our normal peer review. Manuscripts received no later than March 16, 2015 will be considered for inclusion in the special issue. We strongly encourage individuals to contact us in advance with their ideas and ideally a draft title and abstract. Questions or inquiries about the special issue can be directed to the Guest Editor of the issue, Brady Reynolds, PhD, at brady.reynolds@uky.edu or the Editor, Suzette Evans, PhD at se18@columbia.edu. The Biology of Sex and Gender • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Sex as a Form of Motivation Arousal and Satiation The Role of Testosterone Brain Structures and Neurotransmitters Odors, Pheromones, and Sexual Attraction APPLICATION | Of Love, Bonding, and Empathy Concept Check The Biological Determination of Sex Chromosomes and Hormones Prenatal Hormones and the Brain CONCEPT CHECK Gender-Related Behavioral and Cognitive Differences Some Demonstrated Male-Female Differences Origins of Male-Female Differences IN THE NEWS | GTEx Project Provides New Insight Into the Differences Between the Sexes Concept Check Biological Origins of Gender Identity Gender Dysphoria 46 XY Difference in Sexual Development 46 XX Difference in Sexual Development Cognitive and Behavioral Effects APPLICATION | Sex, Gender, and Sports Ablatio Penis and Other Natural Experiments Concept Check Sexual Orientation APPLICATION | Who Chooses a Child’s Sex? The Social Influence Hypothesis Genetic and Epigenetic Influences Prenatal Influences on Brain Structure and Function Social Implications of the Biological Model Concept Check In Perspective Chapter Summary Study Resources After reading this chapter, you will be able to: • Contrast sex with other motivated behaviors. • Demonstrate the role of hormones and brain structures in sexual behavior. • Identify hormonal and brain differences between females and males. • Describe how behavioral differences between males and females are influenced biology and environment. • Explain the role of biological influences on gender identity. • Assess the impact of biological influences on sexual orientation. by Bruce Jenner spent his early career as an athlete, playing football at Graceland College until a knee injury necessitated a change in sport to decathlon in 1968. After years of grueling training and competition, Jenner won a gold medal in decathlon at the 1976 Summer Olympics in Montreal and became a hero back home in the United States. Jenner even graced the cover of Sports Illustrated magazine and became the most widely known athlete to be on the cover of a Wheaties breakfast cereal box. Leaving athletics behind, he became better known as a sports commentator and occasional actor in films and television. During this time he had been married three times and fathered six children. Throughout the successes in athletics and as an actor, Jenner was struggling with a psychological disorder called gender dysphoria, which is the distress that people feel when their gender identity does not match their sex at birth. At times he dressed as a woman, and he was taking female hormones to try to better match his feelings of being female. Master the content. edge.sagepub.com/garrett5e In April 2015, Jenner made news by coming out as a transgendered woman. Later that year, Jenner officially adopted her now-permanent feminine identity as Caitlyn Jenner, and in January 2017, she underwent gender reassignment surgery to replace the penis with a vaginal opening. Her memoir The Secrets of My Life and the documentary series I Am Cait detailed her gender transition; in recognition of her outspoken support for LGBT rights and the strength she demonstrated in discussing her gender identity struggles with the public, she received the Arthur Ashe Courage Award and Out magazine’s Newsmaker of the Year award. Quite possibly the most interesting thing about Caitlyn Jenner’s new gender and identity is that she still finds herself sexually attracted to women, underscoring the fact that gender identity does not always match a person’s sexual orientation. Source: Valerie Macon/AFP/Getty Images. Humans have a great affinity for dichotomies, dividing their world into blacks and whites with few grays in between. No dichotomy is more significant for human existence than that of male and female: One’s sex is often the basis for deciding how the person should behave, what the person can do, and with whom the person should fall in love. Not only are many of the differences between males and females imposed on them by society, but Caitlyn’s experience suggests that typing people as male or female may not be as simple or as appropriate as we think. We will encounter even more puzzling cases later as we take a critical look at the designation of male versus female and the expectations that go with it. In the meantime, we need to continue our discussion of motivation by considering how sex is like and unlike other drives. Sex as a Form of Motivation To say that sex is a motivated behavior like hunger may be stating the obvious. But theorists have had difficulty categorizing sex with other physiological drives because it does not fit the pattern of a homeostatic tissue need. If you fail to eat or if you cannot maintain body temperature within reasonable limits, you will die. But no harm will come from forgoing sex; sex ensures the survival of the species but not of the individual. There are, however, several similarities with other drives like hunger and thirst. They include arousal and satiation, the involvement of hormones, and control by specific areas in the brain. We will explore these similarities as well as some differences in the following pages. Arousal and Satiation The cycle of arousal and satiation is the most obvious similarity between sexual motivation and other motivated behaviors such as hunger and thirst. In the 1960s, William Masters and Virginia Johnson conducted groundbreaking research on the human sexual response. Until then, research had been limited to observing sexual behavior in animals or interviewing humans about their sexual activity. Masters and Johnson (1966) observed 312 men and 382 women and recorded their physiological responses during 10,000 episodes of sexual activity in the laboratory. This kind of research was unheard of at the time; in fact, the researchers had trouble finding journals that would publish their work. Their work on human sexual behavior was the subject of the recent Showtime cable series Masters of Sex. How is sex like and unlike other drives? Masters and Johnson identified four phases of sexual response (Figure 7.1). The excitement phase is a period of arousal and preparation for intercourse. Both sexes experience increased heart rate, respiration rate, blood pressure, and muscle tension. The male’s penis becomes engorged with blood and becomes erect. The female’s clitoris becomes erect as well, her vaginal lips swell and open, the vagina lubricates, her breasts enlarge, and the nipples become erect. While hunger is mostly a function of time since the last meal, sexual arousal is more influenced by opportunity and sexual stimuli such as explicit conversation or the presence of an attractive person. In contrast to humans, sexual arousal in most mammal species is triggered by a surge in hormones. Another difference between sex and other drives is that we usually are motivated to reduce hunger, thirst, and temperature deviations, but we seek sexual arousal. This difference is not unique, though; for example, we might skip lunch to increase the enjoyment of a gourmet dinner. During the plateau phase, the increase in sexual arousal levels off. Arousal is maintained at a high level for seconds or minutes, though it is possible to prolong this period. The testes rise in the scrotum in preparation for ejaculation; vaginal lubrication increases and the vaginal entrance tightens on the penis. During orgasm, rhythmic contractions in the penis are accompanied by ejaculation of seminal fluid containing sperm into the vagina. Similar contractions occur in the vagina. This period lasts just a few seconds but involves an intense experience of pleasure. Orgasm is similar to the pleasure one feels after eating or when warmed after a deep chill, but it is unique in its intensity; the resolution that follows is reminiscent of the period of quiet following return to homeostasis with other drives. After orgasm, males have a refractory phase, during which they are unable to become aroused or have another orgasm for minutes, hours, or even days, depending on the individual and the circumstances. Females do not experience a refractory period and can have additional orgasms anytime during the resolution phase. When comparing the sex drive with other kinds of motivation, the male refractory period has an interesting parallel with sensory-specific satiety (see Chapter 6); it is called the Coolidge effect. According to a popular but probably questionable story, President Coolidge and his wife were touring a farm when Mrs. Coolidge asked the farmer whether the flurry of sexual activity among the chickens was the work of one rooster. The farmer answered yes, that the rooster copulated dozens of times each day, and Mrs. Coolidge said, “You might point that out to Mr. Coolidge.” President Coolidge, so the story goes, then asked the farmer, “Is it a different hen each time?” The answer again was yes. “Tell that to Mrs. Coolidge,” the president replied. Whether the story is true or not, the Coolidge effect—a quicker return to sexual arousal when a new partner is introduced—has been observed in a wide variety of species. We will visit the subject again shortly. Figure 7.1 Phases of the Sexual Response Cycle. Source: From Psychology: The Adaptive Mind (2nd ed.), by J. S. Nairne, 2000, Wadsworth, a part of Cengage Learning, Inc. The Role of Testosterone As important as sex is to humans, it is ironic that so much of what we know about the topic comes from the study of other species. One reason is that research into human sexual behavior was for a long time considered off-limits, and funding was hard to come by. Another reason is that sexual behavior is more “accessible” in nonhuman animals; rats have sex as often as 20 times a day and are not at all embarrassed to perform in front of the experimenter. In addition, we can manipulate their sexual behavior in ways that would be considered unethical with humans. Hormonal control in particular is more often studied in animals because hormones have a clearer role in animal sexual behavior. Castration, or removal of the gonads (testes or ovaries), is one technique used to study hormonal effects because it removes the major source of sex hormones; castration results in a loss of sexual motivation in nonhuman mammals of both sexes. Sexual behavior may not disappear completely, because the adrenal glands continue to produce both male and female hormones, though at a lesser rate than the gonads. The time course of the decline is also variable, ranging from a few weeks to five months in male rats (J. M. Davidson, 1966); across several species, animals who are sexually experienced are impaired the least and decline the slowest (B. Hart, 1968; Sachs & Meisel, 1994). Humans are less at the mercy of fluctuating hormone levels than other animals, but when they are castrated (usually for medical reasons, such as cancer), sexual interest and functioning decrease in both males and females (Bremer, 1959; Heim, 1981; Sherwin & Gelfand, 1987; Shifren et al., 2000). The decline takes longer in humans than in rats, but the rate is similarly variable. Castration has been elected by some male criminals in the hope of controlling aggression or sexual predation, sometimes in exchange for shorter prison sentences. Castration is an extreme therapy; drugs that counter the effects of androgens (a class of hormones responsible for a number of male characteristics and functions) are a more attractive alternative. Those that block the production of the androgen testosterone, the major sex hormone in males, have been 80%–100% effective in eliminating deviant sexual behavior such as exhibitionism and pedophilia (sexual contact with children), along with sexual fantasies and urges (A. Rösler & Witztum, 1998; Thibaut, Cordier, & Kuhn, 1996). Chemical castration is either allowed on a voluntary basis or mandated for some offenses in nine states in the United States (M. Park, 2012) and in several other countries. The effects of castration indicate that testosterone is necessary for male sexual behavior, but the amount of testosterone required appears to be minimal; men with very low testosterone levels can be as sexually active as other men (Raboch & Stárka, 1973). Frequency of sexual activity does vary with testosterone levels within an individual, but the testosterone increases appear to be the result of sexual activity rather than the cause. For example, testosterone levels are high in males at the end of a period in which intercourse occurred, not necessarily before (J. M. Dabbs & Mohammed, 1992; Kraemer et al., 1976). A case report (which is anecdotal and does not permit us to draw conclusions) suggests that just the anticipation of sex can increase the testosterone level. Knowing that beard growth is related to testosterone level, a researcher working in near isolation on a remote island weighed the daily clippings from his electric razor. He found that the amount of beard growth increased just before planned visits to the mainland and the opportunity for sexual activity (Anonymous, 1970). Figure 7.2 Female-Initiated Activity During the Menstrual Cycle. Source: From figure 2 from “Rise in Female-Initiated Sexual Activity at Ovulation and Its Suppression by Oral Contraceptives,” by D. B. Adams, A. R. Gold, and A. D. Burt, 1978, New England Journal of Medicine, 299(21), pp. 1145–1150. In most mammals, females are unwilling to engage in sex except during estrus, a period when the female is ovulating, sex hormone levels are high, and the animal is said to be in heat. Human females and females of some other primate species engage in sex throughout the reproductive cycle. Studies of sexual frequency in women have not shown a clear peak at the time of ovulation. However, initiation of sex is a better gauge of the female’s sexual motivation than is her willingness to have sex; women do initiate sexual activity more often during the middle of the menstrual cycle, which is when ovulation occurs (Figure 7.2; D. B. Adams, Gold, & Burt, 1978; S. M. Harvey, 1987). The researchers attributed the effect to estrogen, a class of hormones responsible for a number of female characteristics and functions. Their reasons were that estrogen peaks at midcycle and the women did not increase in sexual activity if they were taking birth control pills, which level out estrogen release over the cycle. However, testosterone peaks at the same time, and the frequency of intercourse during midcycle corresponds to the woman’s testosterone level (N. M. Morris, Udry, Khan-Dawood, & Dawood, 1987). At menopause, when both estrogen and testosterone levels decline, testosterone levels show the most consistent relationship with intercourse frequency (McCoy & Davidson, 1985). How to interpret these observations is unclear, because testosterone increases in women as a result of sexual activity, just as it does in men (Figure 7.3; J. M. Dabbs & Mohammed, 1992). However, studies in which testosterone level was manipulated demonstrate that it also contributes to women’s sexual behavior. Giving a dose of testosterone to women increases their arousal during an erotic film (Tuiten et al., 2000). More important, in women who had their ovaries removed, testosterone treatment increased sexual arousal, sexual fantasies, and intercourse frequency, but estrogen treatment did not (Sherwin & Gelfand, 1987; Shifren et al., 2000). Figure 7.3 Relationship Between Sexual Behavior and Salivary Testosterone Levels in Men and Women. Source: From “Male and Female Salivary Testosterone Concentrations Before and After Sexual Activity,” by J. M. Dabbs, Jr. and S. Mohammed, Physiology and Behavior, 52, pp. 195–197, Fig. 1. © 1992 Reprinted with permission from Elsevier Science. Brain Structures and Neurotransmitters As neuroscientists developed a clearer understanding of the roles of various brain structures, motivation researchers began to shift their focus from drive as a tissue need to drive as a condition in particular parts of the brain. Sexual activity, like other drives and behaviors, involves a network of brain structures. This almost seems inevitable, because sexual activity involves reaction to a variety of stimuli, activation of several physiological systems, postural and movement responses, a reward experience, and so on. We do not understand yet how the sexual network operates as a whole, but we do know something about the functioning of several of its components. In this section, you will see some familiar terms, the names of hypothalamic structures you learned about in Chapter 6. This illustrates an important principle of brain functioning, that a particular brain area, even a very small one, often has multiple functions. What is the role of testosterone in sexual behavior? Two areas are important in sexual behavior in both sexes, the medial preoptic area of the hypothalamus and the medial amygdala. The medial preoptic area (MPOA) is one of the more significant brain structures involved in male and female sexual behavior. (Be careful not to confuse the medial preoptic area with the median preoptic nucleus, discussed in Chapter 6. They are both in the preoptic area, which you can locate in Figure 6.2.) Stimulation of the MPOA increases copulation in rats of both sexes (Bloch, Butler, & Kohlert, 1996; Bloch, Butler, Kohlert, & Bloch, 1993), and the MPOA is active when they copulate spontaneously (Pfaus, Kleopoulos, Mobbs, Gibbs, & Pfaff, 1993; Shimura & Shimokochi, 1990). The MPOA appears to be more responsible for performance than for sexual motivation; when it was destroyed in male monkeys, they no longer tried to copulate, but instead they would often masturbate in the presence of a female (Slimp, Hart, & Goy, 1978). What brain structures are involved in sexual behavior? The medial amygdala also contributes to sexual behavior in rats of both sexes. Located near the lateral ventricle in each temporal lobe, the amygdala is involved not only in sexual behavior but also in aggression and emotions. The medial amygdala is active while rats copulate (Pfaus et al., 1993), and stimulation causes the release of dopamine in the MPOA (Dominguez & Hull, 2001; Matuszewich, Lorrain, & Hull, 2000). The medial amygdala’s role apparently is to respond to sexually exciting stimuli, such as the presence of a potential sex partner (de Jonge, Oldenburger, Louwerse, & Van de Poll, 1992). Figure 7.4 The Sexually Dimorphic Nuclei of the Rat. Source: From “The Neuroendocrine Regulation of Sexual Behavior,” by R. A. Gorski, pp. 1– 58, in G. Newton and A. H. Riesen (Eds.) Advances in Psychobiology (Vol. 2), 1974, New York: Wiley. Reprinted with permission of John Wiley & Sons, Inc. There are other areas that are involved in sexual behavior but only in the behaviors of a single sex. Especially significant for males is the sexually dimorphic nucleus (SDN), located in the preoptic area (de Jonge et al., 1989). The SDN is three to four times larger in male rats than in females (Figure 7.4; He, Ferguson, Cui, Greenfield, & Paule, 2013), and a male’s level of sexual activity is related to the size of the SDN, which in turn depends, at least in part, on protection by testosterone from the cell death that occurs during the pruning stage shortly after birth (He et al., 2013). Destruction of the SDN reduces male sexual activity (de Jonge et al., 1989). The SDN’s connections to other sex-related areas of the brain suggest that it integrates sensory and hormonal information and coordinates behavioral and physiological responses to sensory cues (Roselli, Larkin, Resko, Stellflug, & Stormshak, 2004). Two other hypothalamic structures are also important. The paraventricular nucleus (PVN; see Figure 6.2) is important for male sexual performance and, particularly, for penile erections (Argiolas, 1999). The ventromedial hypothalamusis active in females during copulation (Pfaus et al., 1993), and its destruction reduces the female’s responsiveness to a male’s advances(Pfaff & Sakuma, 1979). Figure 7.5 Dopamine Levels in the Nucleus Accumbens During the Coolidge Effect. Source: From “Dynamic Changes in Nucleus Accumbens Dopamine Efflux During the Coolidge Effect in Male Rats,” by D. F. Fiorino, A. Coury, and A. G. Phillips, 1997, Journal of Neuroscience, 17, p. 4852. © 1997 Society for Neuroscience. Reprinted with permission. For obvious reasons, we know much less about the brain structures involved in human sexual behavior. Functional MRI (fMRI) recording during masturbation has confirmed the involvement of the medial amygdala and PVN in human sexual activity (Komisaruk et al., 2004). PVN neurons are known to secrete the hormone/neuromodulator oxytocin, which contributes to male and female orgasm and the intensity of its pleasure(Carmichael, Warburton, Dixen, & Davidson, 1994). We will see additional results from human research in the discussion of neurotransmitters. We also know that a few brain structures in humans differ in size between males and females. Because their contribution to sexual behavior is not clear and the size differences may also distinguish homosexuals from heterosexuals, we will defer discussion of these structures until we take up the subject of sexual orientation. Sexual behavior involves several neurotransmitters, but dopamine has received the most attention. You saw in Chapter 5 that dopamine level increases in the nucleus accumbens during sexual activity, and in this chapter that stimulation of the medial amygdala releases dopamine in the MPOA. Dopamine activity in the MPOA contributes to sexual motivation in males and females of several species (E. M. Hull et al., 1999). In males, dopamine is critical for sexual performance: Initially, it stimulates D1 receptors, activating the parasympathetic system and increasing motivation and erection of sexual tissues; as dopamine level increases, it activates D2 receptors, which shifts autonomic balance to the sympathetic system, resulting in orgasm and ejaculation. D2 activity also inhibits erection, which probably accounts in part for the sexual refractory period in males. Interestingly, dopamine release parallels sexual behavior during the Coolidge effect. As you can see in Figure 7.5, it increased in the male rat’s nucleus accumbens in the presence of a female, dropped back to baseline as interest waned, and then increased again with a new female (Fiorino, Coury, & Phillips, 1997). The changes occurred even when the male and female were separated by a clear panel, so the dopamine level reflects the male’s interest rather than the effects of sexual behaviors. Our knowledge about the role of dopamine in human sexual behavior is less precise but nevertheless intriguing. Drugs that increase dopamine levels, such as those used in treating Parkinson’s disease and stimulants, increase sexual activity in humans (Evans, Haney, & Foltin, 2002; Meston & Frolich, 2000). The dopamine system has been reported to be active in the ventral tegmental area in males during ejaculation (Holstege et al., 2003) and in the nucleus accumbens in females during orgasm (Komisaruk et al., 2004). This activity likely reflects a reward response, but, significantly, the activated areas also have strong motor output to the pelvic floor muscles, which are important in orgasmic activity. Variations in the gene for the D4 receptor (DRD4) are associated with sexual arousal and functioning (Ben Zion et al., 2006), and one variant is correlated with promiscuity and sexual infidelity (Garcia et al., 2010). Ejaculation is also accompanied by serotonin increases in the lateral hypothalamus, which apparently contributes further to the refractory period (E. M. Hull et al., 1999). Injecting a drug that inhibits serotonin reuptake into the lateral hypothalamus increases the length of time before male rats will attempt to copulate again and their ability to ejaculate when they do return to sexual activity. Humans take serotonin reuptake blockers to treat anxiety and depression, and they often complain that the drugs interfere with their ability to have orgasms. The antianxiety drug buspirone, by contrast, decreases the release of serotonin and facilitates orgasms (Komisaruk, Beyer, & Whipple, 2008). An interesting model for the regulation of gender-related aggressive and bonding behaviors has been proposed in the steroid/peptide theory of social bonds (van Anders, Goldey, & Kuo, 2011). According to this theory, the balance among testosterone, oxytocin, and vasopressin determine behaviors such as aggression and intimacy (Figure 7.6). As you probably guessed, a high testosterone level in either sex increases aggression, but it also impairs the formation of close social bonds. Oxytocin (involved in muscle contractions of sexual tissue and in social bonding) and vasopressin (a potent neuromodulator of brain activity) modulate the form of intimacy and aggression. Antagonistic aggression (which includes social dominance, partner acquisition, and defense of partners and territory) is seen in those with low levels of vasopressin, whereas protective aggression (such as defending children or partners) is seen in those with high levels of vasopressin. Intimacy increases oxytocin, but its interaction with testosterone levels determines whether that intimacy is sexual (if testosterone is high) or nurturing (if testosterone is low). Therefore, testosterone levels determine the relative amount of competitive versus nurturing behaviors an individual expresses, whereas oxytocin determines the relative amount of social bonding versus social isolation. Figure 7.6 The Steroid/Peptide Theory of Social Bonds. Source: From “The Steroid/Peptide Theory of Social Bonds: Integrating testosterone and peptide responses for classifying social behavioral contexts,” by S. M. van Anders, K. L. Goldey, & P. X. Kuo. Psychoneuroendocrinology, 36(9). © Elsevier. Reprinted with permission. Odors, Pheromones, and Sexual Attraction Sexual behavior results from the interplay of internal conditions, particularly hormone levels, with external stimuli. Sexual stimuli can be anything from brightly colored plumage or an attractive body shape to particular odors. Here we will examine the role of odors and pheromones in sexual attraction, with emphasis on how important they might be for humans. Before we launch into this discussion, we need to have a basic understanding of the olfactory (smell) system. Olfaction is one of the two chemical senses, along with taste. Airborne odorous materials entering the nasal cavity must dissolve in the mucous layer overlying the receptor cells; the odorant then stimulates a receptor cell when it comes in contact with receptor sites on the cell’s dendrites (Figure 7.7). Axons from the olfactory receptors pass through openings in the base of the skull to enter the olfactory bulbs, which lie over the nasal cavity. From there, neurons follow the olfactory nerves to the nearby olfactory cortex tucked into the inner surfaces of the temporal lobes. Figure 7.7 The Olfactory and Vomeronasal Systems. By varying the number of components in odor mixtures, researchers have calculated that humans can distinguish a trillion odors (Bushdid, Magnasco, Vosshall, & Keller, 2014). But we do not have a different receptor for each odor, and an individual neuron cannot produce the variety of signals required to distinguish among so many different stimuli. Researchers have discovered that humans have around 400 different receptor genes that produce an equal number of receptor types, but additional alleles of some of these genes brings the total to about 600 (Olender et al., 2012). Variation in these alleles among individuals suggests considerable variation in what different people can smell. We’re pikers compared with dogs (800); mice (1,100); and the African elephant, which has 2,000 different receptor genes (Niimura, Matsui, & Touhara, 2016). Research has shown that elephants can distinguish people from different tribes by odor and can recognize up to 30 different family members. There is a good argument to be made for the nose as a sexual organ. The most convincing evidence comes from the study of pheromones,airborne chemicals released by an animal that have physiological or behavioral effects on another animal of the same species. Most pheromones are detected by the vomeronasal organ (VNO), a cluster of receptors also located in the nasal cavity. The VNO is illustrated in Figure 7.7, although you will soon see that most researchers believe that it is no longer functional in humans, the victim of evolution as our ancestors developed color vision and came to rely on visual sexual signals (I. Rodriguez, 2004). However, a VNO may not be entirely necessary, because some pheromones and pheromone-like odors can be detected by the olfactory system when an animal’s VNO has been blocked or eliminated surgically (Wysocki & Preti, 2004). The VNO’s receptors are produced by a different family of genes, and the VNO and olfactory systems are separate neurally (P. J. Hines, 1997). Not surprisingly, in animals the VNO’s pathway leads to the MPOA and the ventromedial nucleus of the hypothalamus, as well as to the amygdala (Keverne, 1999). Pheromones can be very powerful, as you know if your yard has ever been besieged by all the male cats in the neighborhood when your female cat was “in heat.” The female gypsy moth can attract males from as far as two miles away (Hopson, 1979). Pheromones provide cues for kin recognition in animals, influence cycling of sexual receptivity in female mice, initiate aggression in both males and females, and trigger maternal behavior in adults and suckling in infants (Wysocki & Preti, 2004). In pigs, the boar exudes androstenone, which elicits sexual posturing and receptivity in sows. In fact, pig farmers use androstenone as an aid in artificial insemination. So, do pheromones play a role in human behavior? In spite of the eagerness with which the media and fragrance industry have embraced the topic, the best answer appears to be “maybe . . . maybe not.” We certainly don’t see pheromones controlling sexual behavior as powerfully as they do in animals; in fact, the best candidate for pheromone control of human behavior is the sucking and searching movements in infants in response to breast odors of a nursing woman (Wyatt, 2016; Wysocki & Preti, 2004). Early interest in the possibility of human pheromones was spurred by reports that women living together in dorms tended to have synchronized menstrual periods and that this was caused by sweat-borne compounds that altered the frequency of luteinizing hormone release (Preti, Cutler, Garcia, Huggins, & Lawley, 1986; Preti, Wysocki, Barnhart, Sondheimer, & Leyden, 2003; K. Stern & McClintock, 1998). Later studies have failed to demonstrate menstrual synchrony almost as often as they have succeeded, and the results have been questioned on methodological grounds (Z. Yang & Schank, 2006). Is there evidence for pheromones in human sexual behavior? Several other studies have claimed evidence for an influence of pheromones, or at least body odors, on human behavior. This includes amygdala activation from smelling the sweat of first-time skydivers (Mujica-Parodi et al., 2009); increased intercourse opportunities when using aftershave or perfume containing underarm extracts that enhanced the person’s sexcharacteristic body odor (Cutler, Friedman, & McCoy, 1998; McCoy & Pitino, 2002); higher alcohol consumption and sociability in males after exposure to fertile female odors (Tan & Goldman, 2015); and men’s higher attractiveness ratings of the scent of women’s T-shirts when women were ovulating (Kuukasjärvi et al., 2004). Application: Of Love, Bonding, and Empathy Source: Todd Ahern/Emory University. Prairie voles are a rare exception among mammals; they mate for life, and if they lose a mate they rarely take another partner. The bonding process (as reviewed in L. J. Young & Wang, 2004) begins with the release of dopamine in reward areas during mating. If dopamine activity is blocked by a receptor antagonist, partner preference fails to develop. Sexual activity also releases the neuropeptides oxytocin and vasopressin, which are likewise required for bonding to take place. Either can facilitate bonding in males or females, but oxytocin is more effective with females and vasopressin with males. So does any of this apply to humans, who are also monogamous (more or less)? The most apparent parallel involves oxytocin. Oxytocin not only facilitates bonding but also causes smooth muscle contractions, such as those involved in orgasm and in milk ejection during breastfeeding. Blood levels of oxytocin increase dramatically as males and females masturbate to orgasm (M. R. Murphy, Checkley, Seckl, & Lightman, 1990). Oxytocin also contributes to social recognition, which is necessary for developing mate preferences. Male mice without the oxytocin gene fail to recognize females from one encounter to the next (J. N. Ferguson et al., 2000), and human males are better at recognizing previously seen photos of women after receiving oxytocin (Rimmele, Hediger, Heinrichs, & Klaver, 2009). Men given oxytocin also had more activity in the nucleus accumbens while viewing photos of their partners, and they increased their ratings of their partners’ attractiveness, but not of other women they knew (Scheele et al., 2013). Oxytocin’s bonding effects are not limited to mates and sex partners. Mother-infant bonding is correlated with oxytocin levels during pregnancy and following birth (Feldman, Weller, Zagoory-Sharon, & Levine, 2007), and a gene for the oxytocin receptor is related to parenting sensitivity (Bakermans-Kranenburg & van IJzendoorn, 2008). Oxytocin also apparently explains empathetic behavior in prairie voles. Though we can’t speculate about what the rodents are “feeling,” they respond to a cagemate’s earlier, unobserved stress with increased grooming, and they match the cagemate’s fear response, anxiety-related behaviors, and corticosterone increase (Burkett et al., 2016). Consoling behavior did not occur if the animals received an infusion of an oxytocin receptor antagonist into the lateral ventricles. But there is no shortage of critics. They point out that no human secretion has been identified as a pheromone, including the “putative human pheromones” regularly used in research studies (Wyatt, 2016; Wysocki & Preti, 2004). Although these compounds may have physiological effects, so do plant odors. Pepper oil, fennel oil, and rose oil can change blood pressure and catecholamine levels (including adrenaline), and the scent of lemon oil increases positive mood. In addition, pheromone studies are criticized for their small sample size, lack of statistical power, lack of replication, and publication bias—the tendency to publish positive results and shelve negative ones. In spite of these concerns, at least one of the critics agrees that we’re able to identify family members by odor and that smell may influence our choice of sexual partner, but he attributes these abilities to a finely tuned sense of smell rather than pheromones (Wyatt). In most animals, attraction is fleeting, lasting only through copulation or, at best, till the end of the mating season. For a few species, though, pair bonding occurs for years or for a lifetime, as we see in the accompanying Application. Concept Check Take a Minute to Check Your Knowledge and Understanding • What change in thinking helped researchers see sex as similar to other biological drives? • What roles do estrogen and testosterone play in sexual behavior in humans? • In what ways do sensory stimuli influence sexual behavior? The Biological Determination of Sex Now we need to talk about differences between the sexes and the anomalies (exceptions) that occur. Sex is the term for the biological characteristics that divide humans and other animals into the categories of male and female. Gender refers to the behavioral characteristics associated with being male or female. For our purposes, it will be useful to make two further distinctions: Gender role is the set of behaviors society considers appropriate for people of a given biological sex, whereas gender identity is the person’s subjective feeling of being male or female. The term sex cannot be used to refer to all these concepts, because the characteristics are not always consistent with each other. Thus, classifying a person as male or female can sometimes be difficult. You might think that the absolute criterion for identifying a person’s sex would be a matter of chromosomes, but you will soon see that it is not that simple. Chromosomes and Hormones You may remember from Chapter 1 that when cells divide to produce sex cells, the pairs of chromosomes separate, and each gamete—the sperm or egg—receives only 23 chromosomes. This means that a sex cell has only one of the two sex chromosomes. In mammals, an egg will always have an X chromosome, but a sperm may have either an X chromosome ...
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