Chapter 6 summarizes the changes to medical care in recent years. There is now a greater recognition that the projected social and psychological challenges of genital variations cannot be fixed by surgery. The first international consensus statement on intersex was published in 2006. The statement makes a number of recommendations to improve care. Controversially however, a new term disorders of sex development (and, later, differences in sex development, or DSD) was introduced to replace intersex and hermaphroditism. Biotechnological developments have been advancing rapidly. More has been learned about “normal” and “abnormal” sex development. However, parents still struggle to talk to children about their bodily variations, young people still worry about getting into relationships, childhood genital surgery is still considered the only way out of stigmatization, psychological expertise is still a low priority in specialist services and the huge potential of peer support is not fully realized.

How to talk about variations in sex development is a major theme for impacted individuals and families. This is the topic of Chapter 12. The author summarizes the research literature with caretakers and with adults about the difficulties of disclosure. Considerable criticism has been levied at health professionals for failing to role model affirming communication. For sure there are gaps in health professionals’ talk, but the biggest contributor to the difficulties is to do with the widespread misunderstanding about the biological variations. Psychological care providers are not there to put a cheerful gloss over clients’ negative expressions. However, they can be part of the favorable social condition in which a wider range of meanings about bodily differences are negotiated. In the practice vignette, the author highlights how tentative and uncertain the enabling process is, where a negative view of sex variations is still widely endorsed in the social context.

In a gendered world, doctors and caretakers took for granted that making atypical bodies more typical was a humane way out of a difficult situation for child and family. Had the professionals carried out proper research, they would have learned from their young patients that the approach was physically and psychologically risky. But research on the long-term effects was not carried out, certainly not from the patients’ perspective. There was also no comparison group made up of people growing up with unaltered genital variations. Research with adults is the topic of Chapter 4 of this book. Since the 1990s, a number of outcome studies with adults have identified many problems of childhood surgery, such as multiple operations, scarring, shrinkage, sensitivity loss, unusual genital appearance and sexual difficulties.

Chapter 8 begins by pointing out the current lack of collective clarity about the role of psychological care providers (PCPs) and suggests that researchers and practitioners make collective effort to develop the role of PCPs in sex development in future. Meanwhile it outlines the psychological consultation process that is generic and familiar to most PCPs. The author provides an initial assessment template and summarizes the popular psychotherapeutic interventions. The template is visible in several of the practice vignettes in the ensuing chapters of the book. The author ends the chapter by arguing that the tertiary environment is set up for diagnostic workup and treatment and unsuitable for the kind of ongoing psychosocial input that is needed by individuals and families living in their communities. The author makes a case for PCPs in DSD centers to collaborate with peer support workers to enable nonspecialist providers in the community to contribute to ongoing support for individuals and families.

Chapter 2 begins with a brief summary of typical embryonic development of the urogenital and reproductive systems. Where the sex chromosomes, reproductive organs and the genitalia in combination do not fit the social categories of female and male, doctors and scientists used to call these physical outcomes hermaphroditism and intersex. They debated for a long time on the “true sex” of the individuals but could not agree on which of the biological sex characteristics should count as their true sex – should it be the sex chromosomes, the gonads or the genitals? Although in the age of genetics, much more is known about how the atypical features have developed. At the same time, people who are impacted by the variations are increasingly disputing medical framing of their differences. The twenty-first century was to seed a new and ongoing debate between the new medical term, differences in sex development (DSD) and intersex, which is now reclaimed by many impacted adults.

Chapter 11 of the book reviews potential psychological contributions in the highly charged process of assigning legal gender to a newborn with genital variations. Although a number of psychological theories exist for understanding gender development, it is the brain gender framework that has been singularly privileged in intersex and DSD medicine. However, the decades of research cannot contribute to the certainty professionals and caretakers seek. Psychological care providers (PCPs) have other frameworks to draw from in order to work ethically and pragmatically with families. In the practice vignette, the author envisions how a highly skilled PCP in a high-functioning DSD team could work substantially to help caretakers to cope with uncertainty and minimize the need for psychosocially motivated medical interventions. In the vignette, the psychological care path is in position before medical investigations begin. It remains highly active long after the medical and legal processes are completed. Although the vignette is built around a child diagnosed with 17β-hydroxysteroid dehydrogenase-3 deficiency, the care principles are relevant to legal binary gender assignment for children born with a range of sex development variations.

Not all sex variations are apparent at birth. Sometimes they are internal and therefore not visible, that is, children are born looking like a typical boy or girl. The child may be brought to medical attention much later, for example when puberty does not follow the expected path. Many of these care users were not told the truth about their biological variation because adults believed that the information would harm them. At the same time, the care users also noticed that they were fascinating to health professionals, who may examine them in droves. Some of them did not discover the truth about their diagnosis and the treatment until mid-life.

For children whose external genitalia look different, when surgical safety and techniques improved, it became routine to align the urogenital anatomy of newborns and young children to the assigned gender. The gender-genitalia alignment was believed to be important psychologically for child and family. Because surgeons found it easier to feminize than masculinize the genitalia, most babies with genital variations were assigned female. From the 1990s, some of these adults have spoken out, talking of too many operations, been too often examined by too many and not understanding what was happening.

Inconsolable distress is neither a universal nor inevitable response to inability to have biological children. In Chapter 14, the author criticizes research with clinic samples that has produced a problem-saturated account of childlessness that obscures a wide range of alternative responses. The author examines the influence of pronatalist ideology on people who are impacted by infertility including many people with sex variations. Away from the treatment context, psychological input can guide individuals, couples and groups to explore personal meaning of nonparenthood. It can facilitate service users to grieve for what is not possible, challenge feelings of deviance and shame, reengage with a range of life goals and, perhaps most important of all, recast adult identities. Through the practice vignette built around a heterosexual couple, one of whom has a late diagnosis of Klinefelter syndrome, the author teases out the difficulties of working psychologically in a treatment context, where complex existential issues and relational dynamics are compressed into the frame of pressurized treatment decisions.

Psychological care is endorsed in DSD medicine. Psychosocial research has been on the increase. But these positive moves have not given psychological practice the kind of collective focus that is enjoyed by the biomedical disciplines. However, psychological care providers have a wide variety of thinking tools and practice techniques to draw on, if to work in an ad hoc way at times. These tools and techniques do not change, but some are more useful and relevant than others for this service context. In Chapter 7, the author discusses the strengths and weaknesses of key theoretical frameworks in healthcare psychology. A major weakness of the individualistic models is their lack of capacity to address structural inequalities in psychological wellness and distress. The author introduces aspects of the Power Threat Meaning Framework and describes how to draw from its theoretical richness to think systemically about what sex variations pose to individuals and families in the social context and how they are responded to. The Framework provides the theoretical backbone for some of the practice vignettes in the final section of the book (Chapters 9–14).

In the 1990s, some former patients mounted street protests in front of medical conferences to draw attention to their trauma. They reclaimed intersex as a personal identity and campaigned for healthcare reform. These developments are the focus of Chapter 5. Intersex is coming out of the closet more and more, through being a topic in television documentaries, novels, films and art. Intersex activists challenge medical authority to change practice. Furthermore, they are not waiting for doctors and scientists to come to their viewpoints. They have successfully lobbied human rights agencies to position childhood genital surgery as a violation of their human rights. They demand that surgery is delayed until the child can give informed consent or is at least old enough to participate in the discussion and offer their agreement.

Bisexual behavior is an order of magnitude more common than exclusive homosexuality in women. Many evolutionary hypotheses on sexual orientation have focused on homosexuality, particularly in men, yet there has recently been a growing recognition that male and female homosexuality may have different evolutionary origins, and that the various forms of nonheterosexuality in the female sexual orientation spectrum may arise via discrete evolutionary–developmental mechanisms. Evolutionarily informed sex research therefore has the fascinating task of understanding the whole spectrum of female sexual orientation – from heterosexual, mostly heterosexual, and bisexual women through to exclusively homosexual women, and from feminine femmes to masculine butches – including the proximate mechanisms and ultimate functions that underlie that variation. Here, we address that task by applying Tinbergen’s four questions to analyze female bisexuality, synthesizing existing research on proximate mechanisms, ontogeny, phylogeny, and ultimate functions. Research in psychology and behavioral sciences indicates that bisexual women comprise a group distinct from heterosexual women and, on some metrics, even from lesbian women: bisexual women have more male-typical personality traits, more unrestricted sociosexual attitudes and behaviors, higher sexual responsiveness, earlier reproduction, higher substance use, higher incarceration rates, and worse health outcomes than heterosexual women. There is broad evidence from across mammalian species that indicates that individual differences in prenatal exposure to sex hormones creates individual differences in brain morphology, cognition, behavioral predispositions, and even life outcomes. They are typically studied in a sex differences framework, but there is now enough evidence to suggest that sexual orientation differences along these parameters can also be robust and informative. We review ten ultimate-level hypotheses on the evolution of female bisexuality and conclude that four hypotheses – balanced polymorphism of masculinity, sexually antagonistic selection, hormonally mediated fast life history strategy, and by-product – are currently best supported by evidence. These hypotheses are also consilient with the wealth of neurodevelopmental evidence on the masculinization of the brain and behavior, which is thought to underlie variation in female sexual orientation. By synthesizing ultimate functions with proximate mechanisms – combined with powerful mid-level frameworks such as life history theory – evolutionary scientists are in a stronger position to provide a comprehensive account of the phenotypic variation observed in the female sexual orientation spectrum.

Compared to the body of literature on male homosexuality, the continuum of bisexual orientations between the exclusively homosexual and heterosexual poles has been largely overlooked in the scientific and evolutionary literature. Possibly, male bisexuality is not as hard a puzzle to evolutionary thinking because it does not reduce individual direct reproductive success as much as exclusive male homosexuality. Or, bisexual men are expected to fall in between the exclusive poles of sexual orientation, and they thus would not differ from them in the studied characteristics. Moreover, the existence of bisexual men has sometimes been doubted or denied in scientific and lay literature. Despite recent Western biphobia (and homophobia) aimed specifically at men, we show that different forms of male sexuality aimed at both men and women are common among different human populations and non-human species, making it a viable candidate for evolutionary analysis. We first outline the concept and measurements of male bisexuality, its prevalence, and after reviewing the proximate socio-biological factors associated with male bisexuality, we outline evolutionary hypotheses on male bisexuality. We show that several hypotheses originally designed to explain exclusive homosexuality apply also to bisexuality, although most of them deal with the more feminine form of male non-heterosexuals. Finally, we outline the importance of studies on bisexuality for evolutionary psychological science.

Human female sexual orientation has received increased attention from scholars in evolutionary and sexuality-related sciences. As our understanding of female sexual orientation matures, especially same-sex attractions, many of our scientific assumptions must similarly progress. Better operational definitions will help focus current theoretical frameworks for understanding same-sex attraction among females, and guide future refinements to these models. Here we advocate for more precise characterization of the female sexual orientation spectrum, which in turn forces reconsideration of two pervasive assumptions in this domain. The first is that female sexual orientation is accurately characterized as a smooth unidimensional continuum. While concepts and terminology that aid our understanding of female same-sex attraction often convey stepwise gradations along a sexual orientation spectrum, we present relevant considerations for treating categories of female sexual orientation as more dissociable than typically acknowledged. Reframing this discussion leads naturally to reconsidering a second assumption – that all female same-sex attractions require adaptationist explanations, or the same kind of evolutionary account. Here we propose that most female non-heterosexuality poses little or no challenge to Darwinian frameworks, although evolutionary considerations can nonetheless help our understanding of the proximate development of such attractions.

As mental health practitioners, we will encounter the broad and diverse range of sexual orientations and gender identities within the people we serve. In this chapter we focus on the cultural diversity of genders and sexualities, and the effects of marginalisation, interpersonal and intimate partner violence and abuse on people’s mental health (Bosse et al., 2018). We describe the ways in which mental health practitioners are able to practise empathically and effectively in gender, diversity, and disclosures of violence and abuse. Throughout the chapter, we will be reading Riley’s story to help us understand how mental health services can be more supportive and accepting of gender and sexual diversity.