CCP User

Monday, 17 January 2022 18:07

SEGM Guide


Dianna T Kenny

In the Booker prize winning book, Shuggie Bain, author, Douglas Stuart, describes his experience growing up “not like a normal boy” in the unforgiving slums of East Glasgow in Thatcher’s 1980s. As he slowly awakens to the reality that he is not like other boys, 

“[h]e… tried to find something masculine to admire about himself: the black curls, the milky skin, the high bones in his cheeks. He caught the reflection of his own eyes in the mirror. It wasn't right. It wasn't how real boys were built to be” (p. 11).

With no one to guide him, Shuggie struggles with the gulf between himself and society’s expectations of masculinity. His brother, Alexander, tries to show him how to walk like a man; he feigns an interest in football and memorizes football statistics in an attempt to “fit in.” Despite his efforts to “fit in” with the other boys in his street, there was nothing he loved more than playing with his mother’s clothes and makeup. These attempts hint at Shuggie’s misapprehensions of masculinity. Shuggie was aware of the difference between himself, his brother, and his peers, but he did not grasp the essence of this difference until many years later. He just knew, as did those around him, that something was “no’ right.” Despite his most earnest wish, his mother would never be cured of her alcoholism and Shuggie was never going to grow up a “normal boy.”

Sexual orientation is one of the developmental achievements that contributes to sexual identity. The four components comprising sexual identity are 

  • understanding of biological sex
  • adoption of a gender identity 
  • social sex-role, and 
  • sexual orientation. In turn, sexual orientation comprises four dimensions: 
    1. sexual attractions(i.e., recognition of those towards whom one feels sexually attracted)[1]
    2. initiation of sexual relationships
    3. disclosure of sexual orientation to others
    4. identity labelling as heterosexual, lesbian/gay or bisexual.[2]More recently, the absence of sexual attraction to either sex has been identified as asexual.[3]

There has been increased interest in understanding how sexual orientation develops across the lifespan but most of the literature in this area involves adolescents and young adults.  Adolescence is considered a pivotal period for the development of sexual orientation.[4] The average age of beginning awareness of same-sex attraction has been estimated at 10 years, following the psychophysiological changes associated with adrenal puberty.[5] However, estimates vary across studies. In one study, the average age of first self-labelling (i.e., as a minority sexual orientation) occurred between 14 and 21. .8 The process of “coming out” (i.e., sexual identity development as lesbian, gay, or bisexual and announcing this orientation to parents, friends ) has been occurring at younger ages than in previous generations, with boys generally reporting knowledge of their minority sexual orientation at younger ages than girls.[6] The reason for this focus in the literature on adolescence is that issues related to sexual orientation are considered unlikely to arise in young children because the concepts outlined above that underpin the concept of sexual orientation will not have developed in the preschool or early primary years; indeed, they usually do not emerge until the child is entering late childhood/early adolescence and has appropriate life experience to understand the biological and social phenomena that are necessary for such an understanding to develop. For some young people, this awareness does not develop until late adolescence and for some, early adulthood. 

Notwithstanding, we have some inklings from novels that homosexual awakening may occur in very young children. A potent example can be found in Christos Tsiolkas’s autobiographical book, 71/2 (2021), in which he describes the lush sensual memories of his five-year-old self of his love for his father’s friend, Stavros, and how these feelings were ignited by other young men with whom he came into contact. Tsiolkas depicts an encounter with a young man in church. 

I stared across at a young man… who had his sleeves folded up on his forearms and the skin is dark and I want to kiss it. I knew that I wanted to kiss it. I wanted to know what it would feel like to rub my lips across the fine black hairs on that arm… Is it possible that even at this tender age I had a premonition of sin? … I knew shame. I saw that God was watching me and I knew that I was tempted by the shaved skin of the men I had looked down on when I was hoisted in my father’s arms.

Homosexuality is currently considered a normal variant of human sexuality. As such, it appears to be a stable polygenic[7] (i.e., multiple genes contributing to a characteristic) trait that occurs on a continuum from bisexual, to mostly gay to exclusively gay.[8] A similar continuum has been identified for mostly to exclusively heterosexual.2

The formation of a minority sexual orientation identity involves four steps: 

  • recognition of same-gender sexual attractions, 
  • initiation of same-sex, intimate relationships, 
  • disclosure of a non-heterosexual sexual orientation to others, and 
  • identification as LGB.[9]The timing of human developmental processes including the development of sexual orientation is varied, as is the order and timing in which these events occur.[10]However, there are no peer reviewed studies that have identified the presence of these four processes in children younger than 8-10 years and even in this age group occurrence is infrequent.

Development of sexual orientation 

Genetic, hormonal, and environmental factors contribute to sexual orientation, with genetic factors contributing approximately 33% of the variance. The most significant environmental influences occur intrauterine but there is continuing debate about what, if any, part is played by the postnatal familial and social environment.[11] 

Many of these factors overlap with those discussed as influential in gender development and will not be repeated here. Because of these commonalities, there is a strong relationship between gendered behaviour in children and sexual orientation in adulthood.[12] For example, a metanalysis of 28 studies (n~5,300) demonstrated a very close association between gendered behaviour in childhood (e.g., rough-and-tumble play, toy and activity preferences, role playing, cross-gender dressing, sex of peer group, appellations of “sissy” or “tomboy,” and stated gender identity) and sexual orientation in adulthood.[13] In boys, disinterest in rough-and-tumble play in childhood correlated with homosexual interest in adulthood.[14],[15]

A more recent study[16] has confirmed earlier findings of the link between childhood gender nonconforming (GNC) behaviour and later sexual orientation. The study comprising 2,428 girls and 2,169 boys from a population-based longitudinal study, the Avon Longitudinal Study of Parents and Children,[17] that followed children born in the 1990s for 15 years, found that the levels of GNC behaviour at ages 3.5 and 4.75 years accurately predicted adolescents’ perceived/stated sexual orientation at age 15 years. The authors argued that the factors contributing to the association between childhood GNC behaviour and sexual orientation may not be primarily socially determined, because children who develop into non-heterosexual adults appear to diverge from gender norms regardless of social encouragement to conform to gender roles. 

Biological factors

There is growing research support for a biological basis to sexual orientation.[18],[19] These include genetic influences, hormonal, and neurobiological factors. 

  • Genetic influences

Sibling studies show more concordance in sexual orientation between monozygotic (i.e., genetically identical, MZ) twins than between dizygotic (i.e., genetically non-identical twins, DZ) or other siblings.[20] A study of 4,900 twins identified a genetic basis for cross-gender behaviour in childhood and homosexual behaviour in adulthood. In male MZ twins, there was a moderate correlation for GNC behaviour in childhood (0.54) and sexual orientation in adulthood (0.51), compared with 0.11 and 0.14, respectively, for male DZ twins. Female MZ twins showed slightly lower associations than male DZ twins between GNC behaviour (0.49) and sexual orientation (0.42) while female DZ twins showed similar concordance for GNC behaviour in childhood (0.45) but no association for sexual orientation in adulthood (0.06).[21] Homosexual male siblings showed similar levels of GNC behaviour and both brothers were either feminine GNC or masculine, suggesting the existence of familial-genetic subtypes of male homosexuality.[22] A number of studies have also identified regions on various chromosomes with linkages to sexual orientation.[23],[24]

  • Hormonal factors

A relationship between prenatal levels of sex steroids and postnatal gender-typed behaviours has been frequently reported. High maternal levels of androgens during pregnancy have been associated with gender nonconformity and same-sex attraction in offspring.[25] It has been suggested that gay men have lower exposure to prenatal androgens than heterosexual men and lesbian women have higher exposure than heterosexual women.[26] Girls with congenital adrenal hyperplasia (CAH) are exposed to higher levels of androgens in utero. They tend to be masculinized in their play as children and are more likely to express bisexual or homosexual orientation in adolescence and young adulthood.[27]

  • Neurobiological factors

Sexually dimorphic toy preferences reflect basic neurobiological differences between boys and girls that precede social or cognitive influences.[28] These sex differences in children’s play commence before gender development and sexual orientation.[29] Nonhuman primates confirm sex differences in novel toy selection observed in young children.[30] In both monkeys and children, males are more rigid in their toy selections than females. Similarly, in maturity, women are more likely to be attracted to both women and men.[31] Further, their sexual attractions appear more context dependent than male sexual attractions.[32] It follows, therefore, that social environments and impacts may exert a greater influence on female compared with male sexual orientation. 

Social factors

Family and social environments

There is little clear evidence that psychosocial factors contribute in any significant way to sexual orientation.[33]However, family composition may affect the likelihood of homosexual orientation in male children.[34]  One of the most compelling findings supporting the influence of familial and social factors on the development of a homosexual orientation is the fraternal-birth-order effect (FBOE).[35] The effect is defined as the higher probability of homosexuality in males with (an) older biological brother(s). Older sisters, older adoptive brothers or stepbrothers do not confer the same effect. The effect pertains even if the older biological brothers grew up apart. The FOBE effect has been observed cross-culturally. The greater the number of older brothers, the greater the probability of homosexual orientation in the youngest brother. The origin of this effect is thought to be intrauterine whereby male-specific antigens on the Y chromosome trigger an immune response in the mother during a first pregnancy with a male foetus. Antibody levels rise with each subsequent male pregnancy, which has the effect of altering sexual differentiation. Recent research has demonstrated that mothers of gay sons have higher antibodies to neuroligin 4 (a Y-linked antigen) than mothers of heterosexual sons.[36] Equally, such a finding could be used to assert the role of hormonal factors in homosexuality since the determinative factor is hormonal occurring in utero but created by family constellation which alters the uterine environment for successive male foetuses. FBOE predicts gender nonconformity in homosexual men.[37]

Lesbian and gay parents may have a higher proportion of biologic lesbian or gay offspring as a result of shared genetic material.[38] Further, lesbian and gay adults, most of whom grew up in heterosexual households, report higher rates of childhood sexual victimization than their heterosexual peers.[39] However, a young person’s same-sex attraction could have preceded the abuse or young people who demonstrate same-sex attraction may be specifically targeted for abuse.[40]

Sexual orientation in women may be more affected by family and social environments compared with men. On average, women reported that they first became aware of their same-sex attractions at age 16 (SD = 8 years),[41] first disclosed their sexual orientation to another person at age 23 (SD = 8 years), and first had sex with another woman at 21 (SD = 7 years).[42] Note the wide standard deviations in each of these average age figures that demonstrate high variability in the timing of these events. Applying the standard deviation to these figures, the youngest age would be eight years. 

Sexual orientation in females appears more likely to change over time.[43] Hypotheses regarding the greater sexual orientation fluidity in females compared with males include biologically based sex differences in foetal hormone exposure and socio-political forces that constrain sexual self-concept, expression, and opportunities differently in women and men.[44] However, there are very few empirical studies with longitudinal data across the life course and across the different dimensions of sexual orientation that can further elucidate fluidity in female sexual orientation.[45]


[1] Bailey, J. M., Vasey, P. L., Diamond, L. M., Breedlove, S. M., Vilain, E., & Epprecht, M. (2016). Sexual orientation, controversy, and science. Psychological Science in the Public Interest, 17(2), 45-101.

[2] Institute of Medicine. (1999). Lesbian health: Current assessment and directions for the future. Washington, DC: National Academy Press.

[3] Bogaert, A. F., & Skorska, M. N. (2020). A short review of biological research on the development of sexual orientation. Hormones and Behavior, 119, 104659.

[4] Perrin, E. C. (2002). Sexual orientation in child and adolescent health care. New York: Kluwer Academic/ Plenum Publishers.

[5] Herdt, G., & McClintock, M. (2000). The magical age of 10. Archives of Sexual Behaviour, 29, 587.

[6] Floyd, F. J., & Bakeman, R. (2006). Coming-out across the life course: Implications of age and historical context. Archives of Sexual Behaviour, 35, 287–296.

[7] Ganna, A., Verweij, K. J., Nivard, M. G., Maier, R., Wedow, R., Busch, A. S., ... & Zietsch, B. P. (2019). Large-scale GWAS reveals insights into the genetic architecture of same-sex sexual behavior. Science, 365(6456), eaat7693.

[8] Savin-Williams, R. C., Cash, B. M., McCormack, M., & Rieger, G. (2017). Gay, mostly gay, or bisexual leaning gay? An exploratory study distinguishing gay sexual orientations among young men. Archives of Sexual Behavior46(1), 265-272.

[9] Cass V. (1996). Sexual orientation identity formation: A western phenomenon. In: Cabaj, R. P., & Stein, T. S. (1996). Textbook of homosexuality and mental health. American Psychiatric Association.

[10] Floyd, F. J., & Bakeman, R. (2006). Coming-out across the life course: Implications of age and historical context. Archives of Sexual Behaviour,35(3), 287-296.

[11] Christopher C. H. Cook (2021). The causes of human sexual orientation. Theology & Sexuality, 27, 1, 1-19, DOI: 10.1080/13558358.2020.1818541

[12] Bailey, J. and Zucker, K. (1995). Childhood sex-typed behaviour and sexual orientation: a conceptual analysis and quantitative review. Developmental Psychology, 31, 43-55.

[13] Bailey, J. and Zucker, K. (1995), Childhood sex-typed behaviour and sexual orientation: a conceptual analysis and quantitative review. Developmental Psychology 31:43-55.

[14] McConaghy, N., Buhrich, N. & Silove, D. (1994), Opposite sex-linked behaviour and homosexual feelings in the predominantly heterosexual male majority. Archives Sexual Behaviour, 23:565-577.

[15] Kenneth J. Zucker PhD. (2008) Reflections on the relation between sex-typed behavior in childhood and sexual orientation in adulthood. Journal of Gay & Lesbian Mental Health, 12,1 -2, 29-59.

[16] Li, G., Kung, K. T. F., & Hines, M. (2017). Childhood gender-typed behavior and adolescent sexual orientation: A longitudinal population-based study.  Developmental Psychology, 53(4), 764 -777.

[17] Golding, J., Pembrey, M., Jones, R., ALSPAC Study Team. ALSPAC--the Avon Longitudinal Study of Parents and Children. (2001). I. Study methodology. Paediatric and perinatal epidemiology. 15(1):74-87. DOI: 10.1046/j.1365-3016.2001.00325.x. Also, see

[18] Bailey, J. M., Vasey, P. L., Diamond, L. M., Breedlove, S. M., Vilain, E., & Epprecht, M. (2016). Sexual orientation, controversy, and science. Psychological Science in the Public Interest17(2), 45-101.

[19] LeVay, S. (2016). Gay, straight, and the reason why: The science of sexual orientation. Oxford University Press.

[20] Langstrom, N., Rahman, Q., Carlstrom, E., & Lichtenstein, P. (2010). Genetic and environmental effects on same-sex sexual behaviour: A population study of twins in Sweden. Archives of Sexual Behaviour, 39, 75–80.

[21] Bailey, J., Pillard, R., Neale, M. & Agyei, Y. (1993). Heritable factors influence sexual orientation in women. Archives General Psychiatry, 50:217-223.

[22] Dawood, K., Pillard, R., Horvath, C., Revelle, W. & Bailey, J. (2000), Familial aspects of male homosexuality. Archives of Sexual Behaviour, 29:155-163.

[23] Mustanski, B. S., DuPree, M. G., Nievergelt, C. M., Bocklandt, S., Schork, N. J., & Hamer, D. H. (2005). A genomewide scan of male sexual orientation. Human Genetics, 116(4), 272-278.

[24] Sanders, A. R., Beecham, G. W., Guo, S., Dawood, K., Rieger, G., Badner, J. A., ... & Martin, E. R. (2017). Genome-wide association study of male sexual orientation. Scientific Reports, 7(1), 1-6.

[25] Hines, M., Brook, C., & Conway, G. S. (2004). Androgen and psycho-sexual development: Core gender identity, sexual orientation and recalled childhood gender role behaviour in women and men with congenital adrenal hyperplasia (CAH). Journal of Sex Research, 41, 75–81.

[26] Breedlove, S. M. (2010). Minireview: organizational hypothesis: instances of the fingerpost. Endocrinology, 151(9), 4116-4122.

[27] Green, R. (2008). Childhood cross-gender behavior and adult homosexuality: Why the link? Journal of Gay & Lesbian Mental Health12(1-2), 17-28.

[28] Williams, C. L., & Pleil, K. E. (2008). Toy story: Why do monkey and human males prefer trucks? Comment on “Sex differences in rhesus monkey toy preferences parallel those of children” by Hassett, Siebert and Wallen. Hormones and Behavior, 54(3), 355-358. doi:

[29]. Berenbaum, S. A., Martin, C. L., Hanish, L. D., Briggs, P. T., & Fabes, R. A. (2008). Sex differences in children’s play. Sex differences in the brain:From genes to Behavior, 275, 290.

[30] Hassett, J. M., Siebert, E. R., & Wallen, K. (2008). Sex differences in rhesus monkey toy preferences parallel those of children. Hormones and Behavior, 54(3), 359-364. doi: 10.1016/j.yhbeh.2008.03.008

[31] Cook, C. C. (2021). The causes of human sexual orientation. Theology & Sexuality27(1), 1-19.

[32] Diamond, L.M. (2012). The desire disorder in research on sexual orientation in women: Contributions of dynamical systems theory. Archives of Sexual Behaviour, 41, 73–83 (2012).

[33] Xu, Y., Norton, S., & Rahman, Q. (2020). A longitudinal birth cohort study of early life conditions, psychosocial factors, and emerging adolescent sexual orientation. Developmental Psychobiology, 62(1), 5-20.

[34] Golombok, S. (2000). Parenting: What really counts? Philadelphia: Taylor & Francis.

[35] Blanchard, R. (2018). Fraternal birth order, family size, and male homosexuality: Meta-analysis of studies spanning 25 years. Archives of Sexual Behavior47(1), 1-15.

[36] Garretson, J., & Suhay, E. (2016). Scientific communication about biological influences on homosexuality and the politics of gay rights. Political Research Quarterly69(1), 17-29.

[37] Swift-Gallant, A., Coome, L. A., Aitken, M., Monks, D. A., & VanderLaan, D. P. (2019). Evidence for distinct biodevelopmental influences on male sexual orientation. Proceedings of the National Academy of Sciences116(26), 12787-12792.

[38] Goldberg, A. E. (2010). Lesbian and gay parents and their children: Research on the family life cycle. Washington, DC: American Psychological Association.

[39] Balsam, K. F., Levahot, K., Beadnell, B., & Circo, E. (2010). Childhood abuse and mental health indicators among ethnically diverse lesbian, gay, and bisexual adults. Journal of Consulting and Clinical Psychology, 78, 459–468.

[40] Wilson, H. W., & Widom, C. S. (2010). Does physical abuse, sexual abuse, or neglect in childhood increase the likelihood of same-sex sexual relationships and cohabition? A prospective 30-year follow-up. Archives of Sexual Behaviour, 39, 63–74.

[41] Standard deviation is a number used to tell how measurements for a group are spread out from the average (mean) or expected value. A low standard deviation means that most of the numbers are close to the average. A high standard deviation indicates greater dispersion or distance from the mean value.

[42] Corliss, H. L., Cochran, S. D., Mays, V. M., Greenland, S., & Seeman, T. E. (2009). Age of minority sexual orientation development and risk of childhood maltreatment and suicide attempts in women. The American Journal of Orthopsychiatry79(4), 511–521.

[43] Baumeister, R. F. (2000). Gender differences in erotic plasticity: The female sex drive as a socially flexible and responsive. Psychological Bulletin,126, 347–374.

[44] Diamond, L. M. (2007). A dynamical systems approach to the development and expression of female same-sex sexuality. Perspectives in Psychological Science, 2, 142–161.

[45] 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 Behaviour, 34, 173–183.

Monday, 17 January 2022 18:05


Dianna Kenny, PhD



The term social contagion describes the “spread of phenomena (e.g., behaviours, beliefs, and attitudes) across network ties”[1] (p. 556). Using very large datasets (e.g., Framingham Heart Study) that have collected longitudinal data on original participants (Original cohort), as well as their children (Offspring cohort) and their children’s children (Third generation cohort) and including their spouses, siblings, friends and neighbours, Christakis and Fowler have shown that social network effects, known as clustering, remain strong and can extend to those up to three degrees of separation from the original cohort. Such effects have been demonstrated across a large range of factors by different researchers using differing datasets. Examples include overweight/obesity, sleep patterns, smoking, alcohol abuse, alcohol abstention, marijuana use, loneliness, happiness, depression, cooperation, and divorce among others. Social contagion may apply to gender dysphoria and its rapid, epidemic-like spread across the Western world among adolescents and young people.

Social network analysis, the method applied to study contagions of all kinds, was first developed and used in public health as a way of determining patterns in the spread of diseases (e.g., influenza, HIV/AIDS, COVID) that resulted in pandemics. Its applications have since expanded with the advent of computers, the internet, mobile and smartphones, and social media.  

There are three types of social networks; (i) egocentric (networks assessing a single individual); (ii) sociocentric (social networks in a well-defined social space, such as a hospital or a school); and (iii) open system networks (e.g., globalised markets, social media). Each network consists of nodes (members), ties (between nodes), and measures of centrality, density and periphery or distance between the nodes. Networks with high centrality are the most effective in disseminating information or innovation. A key example is the transactivist lobby that has achieved spectacular success in a short time in changing health care, educational practices and legislation related to transgender individuals. Other characteristics of networks include cohesion (number of connections within a network) and shape (distribution of ties within the network)[2].

There is mounting evidence that the same principles of social contagion apply to and at least partially explain the increase in young people who believe that they are transgender.

Mechanisms of social contagion

  • Peer contagion

Peer contagion is a form of social contagion, defined as a process of reciprocal influence to engage in behaviours occurring in a peer dyad that may be life-enhancing (e.g., taking up a sport, studying for exams, health screening, resisting engaging in negative behaviours, altruism) or life-compromising (e.g., illegal substance use, truanting from school, aggression, bullying, obesity).  Peer contagion has a powerful socializing effect on children beginning in the pre-school years. By early childhood, the time spent interacting with same-age playmates frequently exceeds time spent with parents[3]. Further, characteristics of peer interactions in schools (e.g., aggression, coercive behaviours, mocking peers) are carried over into the home environment[4]. By middle childhood, gender is the most important factor in the formation of peer associations, highlighting the significance of gender as the organizing principle of the norms and values associated with gender identity[5].

  • Deviancy training 

Different mechanisms of transmission of peer influence have been identified. Deviancy training, in which deviant attitudes and behaviours are rewarded by the peer group, has a significant effect on the development of antisocial attitudes and behaviours such as bullying, physical violence, weapon carrying, delinquency, juvenile offending, and substance abuse[6]. Aggression in adolescence becomes more covert and deliberate and takes the form of exclusion, spreading rumours, and suborning relational damage among an adolescent’s friendship network[7]. Interestingly, adolescents associated with peers who engage in instrumental aggression become more instrumentally aggressive, while those associated with peers who engaged in relational aggression become more relationally aggressive, demonstrating the specificity of the effects of peer contagion via the deviancy training. 

  • Co-rumination 

Another form of peer contagion in adolescence is co-rumination, a process of repetitive discussion, rehearsal, and speculation about a problematic issue within the peer dyad or peer group that underlies peer influence on internalizing problems such as depression, anxiety, self-harm, suicidal ideation, and suicide[8]. Co-rumination is more common among adolescent girls[9]  although a similar phenomenon among boys has been observed. Being in a friendship that engages in perseverative discussions on deviant topics has been associated with increased problem behaviour over the course of adolescence. The longer these discussions, the greater the association with deviant behaviour in later adolescence6.

Peer contagion may undermine the effects of positive socializing forces such as schools, rehabilitation programs for young offenders, and treatment facilities for eating disorders, among others. Collecting same-minded adolescents into group programs may be counter-productive because the peer influence impacts of a homogeneous peer group to maintain disordered behaviours may be greater than the program effects of the treatment facility6.

Young people are particularly vulnerable to peer contagion if they have experienced peer rejection, hostility, and/or social isolation from the peer group[10]. On the contrary, protective factors against peer contagion effects include secure attachment to parents, adequate adult supervision and oversight of the young person’s activities, school attendance, and the capacity for self-regulation[11].

 Does social contagion have a causal effect on behaviour uptake?

Establishing a causal role for the effect of peer behaviour on adolescents is difficult because adolescents choose their peer networks; that is, they choose to associate with like-minded adolescents and those exhibiting similar attributes (homophily). This raises the question: Do adolescents choose their peers because they sanction and engage in similar behaviours or can peer social networks explain the uptake of (new) behaviours in individuals in the network? Sophisticated statistical models have been used to tease out the relative contributions of peer selection and peer influence. Correctly attributing the effects of these two factors has important policy implications since most interventions for reducing risky behaviour among adolescents are implemented at the school level[12].

The special case of social contagion via social media

In the world of social media, social contagion takes on a new, less complex, and narrower meaning:

“Unlike the broadcasts of traditional media, which are passively consumed, social media depends on users to deliberately propagate the information they receive to their social contacts. This process…can amplify the spread of information in a social network”[13] (p. 1).

For example, the social network ‘Instagram’ is one of the most popular platforms for adolescents and young people, with 44% reporting Instagram to be an important part of their daily lives[14]. Analysis of content shows that it is a major vehicle for the sharing of mental health issues, including depression, eating disorders, and non-suicidal self-injury (NSSI)[15].

Systematic reviews have identified potential risks and benefits of online activity. On the one hand, it reduces social isolation and offers encouragement, camaraderie, and reduction of self-harm impulses. On the other, it enables, enhances, or triggers potential risks of ‘copycat’ behaviours such as NSSI, suicide, and eating disorders through normalization of pathological behaviours, or vicarious and social reinforcement of these behaviours[16].

Evidence for social contagion among adolescents

Although social ties are generally protective against loneliness, depression, and suicide, social ties can be toxic and can amplify the risk of psychopathology in members of a social network[17]. There is growing evidence of social contagion among adolescents for several psychopathologies that arise in adolescence [e.g., eating disorders[18], marijuana use[19], non-suicidal self-injury16,[20],[21],[22],[23]; and suicide[24],[25]. Intensification of peer influence in closed communities of like individuals, such as schools, inpatient wards, residential units[26], or therapy groups often results in the advocacy of the practices (e.g., self-starvation, compulsive exercise, deceitful practices around eating) associated with anorexia nervosa6. Celebrity suicides also trigger spikes in suicide rates, with the greater visibility of the celebrity and prolonged coverage of the suicide triggering higher spikes and longer duration of elevation of rates of suicide amongst fans[27],[28].

Commentators on the burgeoning incidence of young people claiming that they are transgender assert that peer contagion may underlie this ominous trend.  When we examine the gender dysphoria epidemic in social network terms, we see several features operating. It is an open-system network with nodes and ties expanding across the oceans to the US, UK, Asia, Europe, Scandinavia, and Australia. Most countries are reporting sharp increases in the number of people seeking services and treatment for gender dysphoria. Many are ramping up services and setting up new gender clinics to cope with increased demand. This network is highly centralised with only one voice – the transactivist lobby.  Opinion leaders operating at the centre of these networks are very influential. The level of density in a network has two effects – firstly, it enhances the circulation of information between members and secondly, it blocks the introduction of dissenting ideas and evidence[29], both observable phenomena in the transgender epidemic. 

There is evidence that peer contagion may be a relevant factor in the sharp increases in young people vulnerable to succumbing to gender dysphoria.

  • Low gender typicality, peer victimization, ingroups and the trans-lobby

Low gender typicality (i.e., perceived lack of fit within one’s binary gender) has a significant impact on social acceptance within one’s peer group[30]. It is strongly associated with adjustment difficulties, behavioural problems, lower self-esteem, and increased internalizing disorders (e.g., anxiety, depression)[31]. As children progress to adolescence, peer as opposed to parental acceptance becomes paramount. Peers therefore take over the role of gender socializing agents from parents[32]. Adolescent peers tend to be critical of behaviours, dress, mannerisms, and attitudes that are not gender typical as a way of policing and reinforcing gender norms and respond with criticism, ridicule, exclusion, and even intimidation of non-conformers[33]. Research shows that the problems accruing to low gender typicality are mediated by peer victimization and that reducing peer victimization may ameliorate these difficulties29. Conversely, peer acceptance mediated the self-worth of gender non-conforming 12- to 17- year-olds[34]. Gender non-conformity and gender atypicality have also been associated with higher physical and emotional abuse by caregivers[35]. Mental health is difficult to sustain in the face of caregiver abuse and peer bullying and victimization[36]. Indeed, gender non-conforming and gender atypical youth are at higher risk of depression, anxiety, and suicidality in adulthood[37].

It is tempting to speculate that these groups of young people, searching for homophily (i.e., like peers) started to exaggerate their points of difference from their gender-conforming peers rather than to hide and minimize them to avoid being bullied and excluded. In so doing, they left the “outgroup” of nonconformers and formed an ingroup of extreme gender-nonconformers, transcending the gender barrier altogether and declaring themselves transgender. Suddenly, the discomfort and fear of not being gender typical becomes a virtue and rather than fearing the disapprobation of their peers, their open revolt in declaring themselves transgender is valorised by a politically powerful transactivist lobby. One would expect that gender atypical children who feel both internal and external pressure to be gender conforming would experience greater discomfort[38] and therefore be more susceptible to the message of trans activism. 

Ingroups behave in stereotypical ways with respect to outgroups – they favour ingroup characteristics, assigning more positive attributes to its members and derogating outgroups in order to enhance the status of their ingroup[39]. It is not surprising, then, that members of the transgender ingroup exaggerate the characteristics of the “trans” gender they take on – becoming more “feminine” or “masculine” than heteronormative groups of cismen and ciswomen. Transactivist groups have proliferated and consolidated in a short time by exploiting the characteristics of ingroups and outgroups. For example, social projection (i.e., the belief that other members of the group are similar to oneself) has been a powerful integrating process that simultaneously creates protection for its own members and distance from outgroup members, using the formula, “if you are not with us, you are against us” – those disagreeing with the ideology of the trans-lobby are labelled “transphobic” or TERFS (trans-excluding radical feminists) and publicly denounced. 

  • Rapid onset gender dysphoria (ROGD) and the role of social media 

The upsurge in rapid onset gender dysphoria (ROGD) tends to occur mostly in girls at around age 14, which is an age identified by developmental psychologists to be particularly susceptible to peer influence[40]. For example, a study of peer contagion for risky behaviours found that exposure to risk-taking peers doubled the amount of risky behaviour in middle adolescents, increased it by 50% in older adolescents and young adults, and had no impact on adults[41]. This group of young people were likely to belong to peer groups in which one or more of their friends had become gender dysphoric or transgender identified. Their coming-out announcement to parents also tended to be preceded by recent increases in their daughters’ social media and internet usage.  

Lisa Littman[42] canvassed the perceptions of parents who had children who displayed ROGD during or just after puberty. There were 256 respondents, of whom 83% had daughters, with a mean age of 15.2 years when they declared themselves transgender, 41% of whom had previously expressed a non-heterosexual sexual orientation, and 62.5% of whom had received a diagnosis for a mental health disorder (e.g., anxiety, depression) or a neurodevelopmental disability (e.g., autism spectrum disorder).  Thirty-seven percent (37%) of these young people belonged to peer groups with other members identifying as transgender. Parents also reported a decline in their child’s mental health (47%) and relationship with parents (57%) after declaring themselves transgender. Thereafter, they preferred transgender friends, websites, and information coming from the transgender lobby. 

Recent studies show that contagion is enhanced when online influencers are perceived to have high credibility and reduced when the influencer is perceived to have low credibility. A similar effect is observed if the influencer belongs to an out-group or an in-group[43].

Empirical evidence 

There has been a sharp increase in the population estimates of those identifying as transgender. One study, a meta-regression of population-based probability samples provides compelling evidence of this trend, where estimates more than doubled in the space of eight years from 2007 to 2015[44].

Similarly, upward trajectories of enrolments in GD clinics have been observed in the UK and Australia. Figure 1 summarizes the trends.

Figure 1

Source: Kenny, D.T. (2021). Australian data provided by the gender clinics under freedom of information applications and NIH for UK figures.



Gender dysphoria and its associated ideology highlights yet another worrying psychic epidemic affecting primarily young people that has spread its tendrils into all corners of society – medical, social, legal, psychological, political, ideological, and philosophical. We still do not understand this phenomenon well but there are sufficient indicators with respect to its trajectory to conclude that social contagion is a major player in its dissemination. 


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[12] Ali, M., & Dwyer, D. (2010). Social network effects in alcohol consumption among adolescents. Addictive behaviors, 35(4), 337-342. 

[13] Nathan, O. H., & Kristina, L. (2014). The simple rules of social contagion. Scientific Reports, 4. doi:10.1038/srep04343.

[14] Feierabend, S, Plankenhorn, T, Rathgeb, T (2015).

[15] Fischer, T, Goldwich, AD, Haentzschel, O (2015). Instagram leaks. Neon 5, 16–21.

[16] Brown, R. C., Fischer, T., Goldwich, A. D., Keller, F., Young, R., & Plener, P. L. (2018). # cutting: Non-suicidal self-injury (NSSI) on Instagram. Psychological Medicine48(2), 337-346.

[17] Christakis, N., & Fowler, J. (2008). The collective dynamics of smoking in a large social network. New England Journal of Medicine, 358(21), 2249-2258. 

[18] Allison, S., Warin, M., & Bastiampillai, T. (2014). Anorexia nervosa and social contagion: Clinical implications. Australian & New Zealand Journal of Psychiatry, 48(2), 116-120. doi:10.1177/0004867413502092.

[19] Ali, M., Amialchuk, A., & Dwyer, D. (2011). The social contagion effect of marijuana use among adolescents. PloS one, 6(1), e16183. doi:10.1371/journal.pone.0016183.

[20] Fulcher, J. A., Dunbar, S., Orlando, E., Woodruff, S. J., & Santarossa, S. (2020). Selfharn on Instagram: understanding online communities surrounding non-suicidal self-injury through conversations and common properties among authors. Digital health6, 2055207620922389.

[21] Jarvi, S., Jackson, B., Swenson, L., & Crawford, H. (2013). The impact of social contagion on non-suicidal self-injury: A review of the literature. Archives of Suicide Research17(1), 1-19.

[22] Lloyd-Richardson, E. E., Perrine, N., Dierker, L., & Kelley, M. L. (2007). Characteristics and functions of non-suicidal self-injury in a community sample of adolescents. Psychological medicine, 37(8), 1183.of a rapid onset of gender dysphoria. PloS One, 14(3), e0214157.

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[24] Abrutyn, S., & Mueller, A. S. (2014). Are suicidal behaviors contagious in adolescence? Using longitudinal data to examine suicide suggestion. American Sociological Review, 79(2), 211-227. 

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[26] Huefner, J., & Ringle, J. (2012). Examination of negative peer contagion in a residential care setting. Journal of Child and Family Studies, 21(5), 807-815. doi:10.1007/s10826-011-9540-6.

[27] Fu, K.-w., & Chan, C. (2013). A study of the impact of thirteen celebrity suicides on subsequent suicide rates in South Korea from 2005 to 2009. PloS One, 8(1), e53870. 

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[29] Iyengar, R., Van den Bulte, C., & Valente, T. W. (2011). Opinion leadership and social contagion in new product diffusion. Marketing Science, 30(2), 195-212. 

[30] Sentse, M., Scholte, R., Salmivalli, C., & Voeten, M. (2007). Person–group dissimilarity in involvement in bullying and its relation with social status. Journal of Abnormal Child Psychology, 35(6), 1009-1019. 

[31] Smith, D. S., & Juvonen, J. (2017). Do I fit in? Psychosocial ramifications of low gender typicality in early adolescence. Journal of Adolescence, 60, 161-170. doi:

[32] Blakemore, S.-J., & Mills, K. L. (2014). Is adolescence a sensitive period for sociocultural processing? Annual Review of Psychology, 65, 187-207. 

[33] Zosuls, K. M., Andrews, N. C., Martin, C. L., England, D. E., & Field, R. D. (2016). Developmental changes in the link between gender typicality and peer victimization and exclusion. Sex Roles, 75(5-6), 243-256. 

[34] Roberts, A. L., Rosario, M., Slopen, N., Calzo, J. P., & Austin, S. B. (2013). Childhood gender nonconformity, bullying victimization, and depressive symptoms across adolescence and early adulthood: an 11-year longitudinal study. Journal of the American Academy of Child & Adolescent Psychiatry, 52(2), 143-152.

[35] Roberts, A. L., Rosario, M., Corliss, H. L., Koenen, K. C., & Austin, S. B. (2012). Childhood gender nonconformity: A risk indicator for childhood abuse and posttraumatic stress in youth. Pediatrics, 129(3), 410. 

[36] Aspenlieder, L., Buchanan, C. M., McDougall, P., & Sippola, L. K. (2009). Gender nonconformity and peer victimization in pre-and early adolescence. International Journal of Developmental Science, 3(1), 3-16. 

[37] Alanko, K., Santtila, P., Witting, K., Varjonen, M., Jern, P., Johansson, A., . . . Kenneth Sandnabba, N. (2009). Psychiatric symptoms and same-sex sexual attraction and behavior in light of childhood gender atypical behavior and parental relationships. Journal of Sex Research, 46(5), 494-504.

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[39] Leyens, J.-P., Paladino, P. M., Rodriguez-Torres, R., Vaes, J., Demoulin, S., Rodriguez-Perez, A., & Gaunt, R. (2000). The emotional side of prejudice: The attribution of secondary emotions to ingroups and outgroups. Personality and Social Psychology Review, 4(2), 186-197.

[40] Steinberg, L., & Monahan, K. C. (2007). Age differences in resistance to peer influence. Developmental Psychology, 43(6), 1531-1543. doi:10.1037/0012-1649.43.6.1531.

[41] Gardner, M., & Steinberg, L. (2005). Peer influence on risk taking, risk preference, and risky decision making in adolescence and adulthood: An experimental study. Developmental Psychology, 41(4), 625.

[42] Littman, L. (2019). Correction: Parent reports of adolescents and young adults perceived to show signs of a rapid onset of gender dysphoria. PloS One, 14(3), e0214157.

[43] Andrews, J. J., & Rapp, D. N. (2014). Partner characteristics and social contagion: Does group composition matter? Applied Cognitive Psychology, 28(4), 505-517. doi:10.1002/acp.3024.

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Monday, 17 January 2022 18:02


Dianna Kenny PhD

Gender development is a complex process; it involves an interplay of genes, gonadal hormones, cognitive, language, and socioemotional development, the child’s socialization history, and culture. 

Gender identity includes: 

  • the individual's conviction that s/he is male or female; and
  • a social sex-role, which is the enactment of socially and culturally appropriate displays of femininity and masculinity.[1]

Cognitive processes in gender development

Psychologically, the development of gender concepts follows the same stages as those in the development of object and person constancy. Jean Piaget and colleagues identified four stages of cognitive development based on the different ways that children of different ages and cognitive capacity construct reality.[2] In the first stage (i.e., sensorimotor stage from birth to ~18 months), the infant interacts with the world via his/her senses and motor activity. Through repeated experiences of the physical world, the infant gradually develops schemas or organized patterns of behaviour, which gradually cohere into more complex, higher-order schemas. A process of adaptation then occurs that allows information to be assimilated into the new schema or to be accommodated if new knowledge replaces old, less appropriate schemas for the new object. Feedback from the environment determines which schemas are maintained and elaborated and which fade into disuse. In this process, combinations of visual, auditory, tactile, olfactory, and motor representations of objects are combined to form more complex, complete, and permanent representations of objects (and people) in the real world 

A critical skill acquired at the end of the sensorimotor period is object permanence, defined as the understanding that objects (and people) continue to exist when out of sight. Object permanence is necessary for more complex schema development and for memory. Absence or poorly developed object or person permanence explains the lack of distress in infants in the first few months of life when mother leaves, and the capacity of other caregivers to attend to the child’s needs without protest from the infant. When object permanence is complete, infants understand that their mothers are unique and continue to exist when out of sight, hence their distress when she is absent. Interestingly, babies with secure attachments to their mothers develop person permanence at a younger age than object permanence.[3]

Following Piaget, Kohlberg and Maccoby[4] proposed that the development of gender constancy (i.e., the notion of the permanence of categorical sex) is a necessary precursor to conformity with culturally defined gender norms; in other words, gender cognitions precede gendered behaviour (i.e., “I am a boy; therefore I want to behave like a boy”). According to this cognitive-developmental theory, there are three stages in the acquisition of gender constancy: 

  • identification of one’s own and others’ sex, that is, basic gender identity and labelling;
  • gender stability/gender permanence (i.e., gender remains stable over time); and
  • gender constancy (i.e., gender is a fixed characteristic that is not altered by superficial transformations in appearance or activities). 

As children develop their concept of gender, they initially focus on the perceptual properties of a person (e.g., the person’s name, long or short hair, pink or blue clothes) and act as if these properties are the defining characteristics of that person. They cannot conserve or retain a person’s basic gender identity when outward characteristics change. In other words, they are perceptually bound - they define the concepts of “male” and “female” in terms of outward appearance such as hair, clothing, toys etc rather than in terms of the person’s genitalia or biological sex. Here is an example:

A mother of a three-year-old was visiting with her friend who had just given birth to a son. The child was watching the mother bathe the baby. Mother asked her, “Is this baby a boy or a girl?” to which the child replied, “I don’t know. It hasn’t got any clothes on.”

Some children older than three years continue to have difficulty conserving sex across perceptual transformations and these difficulties may continue up to the age of seven. This is developmentally normal. Even when preschool children do show gender constancy, it is unlikely that they understand its biological basis, a phenomenon called pseudo-constancy.[5] Pseudo-constant children provide correct judgements of gender but with incorrect explanations as to their judgement, while children with true constancy offer both correct judgements and explanations. Pseudo-constancy is a transitional process leading to the attainment of true constancy.

Once gender constancy (i.e., consistency and stability of the concept) is achieved, children display lower levels of rigidity or gender stereotypy in gender-based behaviour and become more flexible in their reactions to culturally derived gender norm violations. This generally occurs around five years of age, although children with gender dysphoria are slower to develop gender constancy and engage in less sex-typical behaviour compared with children who can accurately self-label their gender.[6] Thus, gender constancy becomes an organizing principle for children’s gender beliefs and to some extent, behaviours. Part of the gender development process is the attainment of a sense of the importance of and contentedness with one’s gender. Gender typing, a process whereby the child selectively attends to gender cues, same-sex models, same-sex activities,  and clothing is a function of increasing age and emerging constancy.[7] 

Social processes in gender development

In addition to cognitive factors, social factors[8],[9] are influential in the development of gender concepts. Kagan[10]argued that social sex-roles i.e., gender “typical” behaviours are acquired by:

  • children wanting approval
  • adult caretakers giving children approval for developing stereotypic male or female behaviour; and
  • males learning to behave like boys and females like girls. 

The nature of the relationship between the child and the adult caretaker who is modelling the desired behaviour is important. The adult model must:

  • be perceived by the child as nurturing
  • have resources desired by the child; and 
  • be perceived by the child on some objective basis to be similar to the model. 

The emergence of awareness of sex differences and the display of gender-typical behaviour and preferences occurs primarily within groups after the early gender socialization experiences of infants and toddlers that occurs in families. Developmental Intergroup Theory[11] is one model that explicates the powerful social psychological processes that operate to create group-based adherence to dimensions of social categorization such as race, religion, politics, sexual orientation, and gender. It appears from research in this area that similar social learning processes operate in learning about gender as those that involve other intergroup or categorization experiences. With respect to gender, mothers' and fathers' behaviours are better predictors of children's gender-role attitudes than parents' gender ideology.[12]

Thus, the perception of being male or female is both an individual and a group process in that children, during the course of developing a gender identity, assign themselves to a categorical group membership that asserts new, and reinforces existing gender beliefs and attitudes through modelling and imitation of same-sexed peers and adults. When gendered behaviour is the salient characteristic being observed, children imitate same-sex adults more than same-aged peers, highlighting the importance of same-sex adults as early gender role models. 

On any given day, children are exposed to numerous people exhibiting a variety of behaviors. What they encode as gender normative, however, are those behaviors exhibited most frequently and consistently by multiple members of each gender category[13] (p. 1929). 

Children as a young as three- to four-years of age can self-categorize along the dimension of gender and can adapt their behaviour via imitation according to the social context in which it occurs.

Group processes are critical. For example, according to social learning theory,  children are rewarded for gendered behaviour and this consolidates the cognition, “I must be a boy/girl.”[14] Parents encourage and reinforce sex-typical play in their children from a young age.[15] A strong association has been found between amount of encouragement and level of sex-typical play in normally developing children.[16] By three years of age, children show marked preference for same-sex playmates and these preferences persist independently of parental involvement, even increasing when adults are not present.  

As same-sex imitation increases, cross-sex avoidance heightens, possibly because gender constancy has not yet been fully attained. “Self-categorization in terms of a social identity maximizes both differences between one's in-group and an out-group and similarities between oneself and other in-group members”11 (p. 1929). 

The impact of families on gender identity development

“Parents are critical mediators of the experiences of their gender variant children…”[17] (p. 123), as indeed are siblings, peers, and the wider ecological context in which children grow and learn.

Individual differences in children’s gender role development emerge as a result of both structural (e.g., family parental constellation – single parent, lesbian/gay, heterosexual) and process factors (e.g., beliefs and attitudes, gender-related behaviours, division of paid and unpaid labour) in families. It is important to disentangle family structure variables (i.e., parental sexual orientation) from family process variables (i.e., attitudes and behaviours). Research has identified family process variables to be more strongly associated with children’s gender development than family structure variables.[18]

Research on children reared by heterosexual parents indicates that individual differences in gender development covaries with differences in parental attitudes and practices. For example, when parents hold more conservative attitudes about gender-related issues, and when they divide household labour along traditional, gender-specialized lines, their children are likely to label their own gender as well as that of others earlier than children of more egalitarian parents. Those children who learn gender labels earlier are also likely to have more extensive knowledge of gender role stereotypes, and more traditional gender-related preferences and behaviours. However, during the preschool period, even children of more liberal parents often report strong same sex-typed preferences like children with more conservative parents.[19]

Studies in the developmental psychology literature about factors that influence gender development in traditional families[20],[21],[22] can inform and guide research into families with a transgender child. These include the interpersonal quality of parent-child[23] and sibling relationships[24], and parental gender attitudes and behaviours[25],[26].   One study of traditional families found that preadolescent children who are anxiously attached or who had a preoccupied form of insecure attachment to their mothers experienced lower gender contentedness and fewer gender-typical feelings compared with securely attached children[27].

A study of sibling effects on gender development and identification found that boys and girls with same-sexed older siblings were more sex-typed than same-aged, same-sexed singleton children, who, in turn, were more sex-typed than children with opposite-sex siblings. Having an older brother was associated with more masculine behaviours in both younger male and female siblings25.  In a three-year longitudinal study of first-born sibling influences on second-born children, McHale et al20 reported that elder siblings influenced the gender role attitudes and behaviours in their younger siblings, but that parents exerted more influence over gender role in first-borns compared with second-born siblings. These findings raise interesting questions, for example, whether an abusive elder brother may figure disproportionately in the family constellations of later-born sisters who eventually transition from female-to-male. 

Childhood maltreatment is frequently found in the medical histories of gender dysphoric individuals, with one study reporting that 25 percent of a sample of 109 adult male-to-female transgender persons disclosed child maltreatment[28], with more serious maltreatment being associated with higher body dissatisfaction.


The role of biological factors in gender identity development

Biological factors also make a significant contribution to gender identity development and gender dysphoria.  These include (i) genetic factors as evinced, for example, by higher concordance of transgenderism among monozygotic compared with dizygotic twins[29]; (ii) neuroanatomical factors related to the sexual differentiation of the genitals and the brain[30]; (iii) developmental disorders, in particular autism spectrum disorder[31],29; (iv) neuropsychiatric morbidity[32]; and (v) endocrine factors[33].

Recent research in both humans and primates shows that sexually dimorphic toy preferences reflect basic neurobiological differences between boys and girls that precede social or cognitive influences.[34] Children’s gendered selections of playmates, toys, and activities can be traced to the influence of biological factors, in particular, prenatal exposure to testosterone that occurs via testicular development, which in turn is determined by the presence of the Y chromosome.[35]

These sex differences in children’s play commence very early, before gender development and sexual orientation.[36]Studies with nonhuman primates, who have not been affected by gendered socialization processes or gender identification, confirm sex differences in novel toy selection (e.g., males prefer wheeled toys, females prefer plush toys, dolls) observed in young children.[37] In both monkeys and children, males are more rigid in their toy selections than females. However, girls who have been exposed to abnormally high levels of testosterone, such as those with congenital adrenal hyperplasia (CAH),[38] and those whose mothers took androgenic progestins during pregnancy show increased male-typical play and toy selection.[39] Further, levels of testosterone in the blood or amniotic fluid of pregnant women are associated with the degree of male-typical behaviour demonstrated by their children.[40]  As well as sex-nontypical behaviour in childhood, women with CAH evince lower heterosexual orientation, diminished identification with female gender, and higher preference to live as a man in adulthood, despite having been raised as girls. CAH women are 600 times more likely than women in the general population to experience severe gender dysphoria.21

Some personality characteristics such as empathy (higher in females) and aggression (higher in males) are also associated with prenatal testosterone exposure.[41] Hormonal surges in sex hormones (testosterone for boys, and oestrogen for girls) soon after birth may also affect gender development. Those children who have absent or reduced hormonal surges such as boys with hypogonadism and girls with Turner’s syndrome show differential deficits in developments normally associated with their assigned sex.[42]

Biological factors other than testosterone can also affect gender development. For example, newborns can generally be assessed along nine dimensions of infant temperament - activity level, distractibility, intensity, regularity, sensory threshold, approach/withdrawal, adaptability, persistence, and mood.[43]  Zucker and colleagues[44] offer a highly cogent example of how infant temperament can interact with gender development processes to cause confusion about gender identity in young people. Activity level, a sex-dimorphic trait that tends to be higher in boys, is associated with higher physical energy expenditure, one form of which is rough-and-tumble play. Activity level is lower in boys and higher in girls with gender identity disorder (GID) – an inversion of levels that occur in children without GID. Boys low in activity level might find the behaviour of girls more compatible with their temperament, leading them to affiliate with girls, which may direct their toy and play interests towards those typical of girls. This process, if continued, may lead to the development of female gender identity and later to gender confusion and/or dysphoria. This process may be interrupted if boys with low activity level meet and befriend other boys with similar activity levels (e.g., boys who prefer reading and playing chess rather than playing body contact sports). Meeting like, same-gendered minds may make it possible for such boys to expand their previously-held, somewhat rigid views about the nature of boys, thus allowing them to view themselves as a subset of all males, rather than as females “trapped in the wrong body.” 


Gender development is a multifaceted process involving genetic, biological, cognitive, and social factors. These factors are not monoliths acting independently. Rather, they form a complex set of interactions that influence gender development, perhaps in different ways for different children. Detailed examination of the child’s life including their primary caregivers, family constellation and peer relationships needs to be undertaken to understand the complex issues associated with gender development and its pathologies. Gender dysphoria might be better understood as a relational process rather than an inherent property of the individual[45]. Illuminating the interactional dynamics[46] in which young children assert that they are transgender may elucidate the complex interplay of cognitive, social and biological factors at play. 


[1] Shively, M. G., & De Cecco, J. P. (1977). Components of sexual identity. Journal of Homosexuality, 3(1), 41-48. doi:10.1300/J082v03n01_04

[2]Piaget, J. (1942). The three fundamental structures of psychic life: rhythm, equilibrium, and grouping. Psychologie, 1, 9-21. 

Piaget, J. (1947). The psychology of intelligence. Oxford, England: Armand Colin.

Piaget, J., & Cook, M. (1954). The construction of reality in the child. New York: Basic Books.

Piaget, J., & Cook, M. (1954). The development of causality. In The construction of reality in the child (pp. 219-319). New York: Basic Books.

Piaget, J., & Inhelder, B. (1969). The psychology of the child. London: Routledge and Kegan Paul.

[3] Kenny, D.T. (2013). Bringing up baby: The psychoanalytic infant comes of age. London: Karnac. 

[4] Kohlberg, L., & Maccoby, E. (1966). The development of sex differences. Stanford, USA: Stanford University Press.

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