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Early Androgens Are Related to Childhood Sex-Typed Toy Preferences
Abstract
Girls with cong~nital adr~nal hyp~rplasia (CAR) who w~r~ ~xpos~d to high '~v~ls 01 andro,~n in th~ pr~natal and ~arly postnatal p~riods show~d in- cr~as~dp/Qy with boys' toys and r~duc~d play with girls' toys compar~d with th~ir un~xpos~d I~ma/~ r~/atives at a,~s 3 to 8. Boys with CAR did not differ from th~ir ma/~ r~/atives in play with boys' or girls' toys. Th~se r~sults sugg~st that early hormon~ exposur~ in/~males has a masculinizing ~ff~ct on s~x-typ~d toy pr~/erences. the patient or control status of subjects. We hypothesized that CAH girls would show 8feater preference for boys' toys than their unaffected female relatives, and reduced preference for girls' toys. We did not predict effects for CAH boys because androgen treatment has incon. sistent effects in male experimental ani- mals (Baum &. Schretlen, 197.5; Dia. mond. Llacuna, & Wong, 1973).
... Regarding children's play preferences, girls with CAH have been found to be more likely than unaffected girls to show increased preferences for boy-typical toys (e.g., vehicles) and reduced preferences for girl-typical toys (e.g., dolls) (Berenbaum and Hines, 1992;Berenbaum and Snyder, 1995;Dittmann et al., 1990;Ehrhardt and Baker, 1974;Meyer-Bahlburg et al., 2004;Nordenström et al., 2002;Pasterski et al., 2005;Pasterski et al., 2011;Servin et al., 2003). They also have usually been found to show increased interest in male-typical activities (e.g., rough-and-tumble play; Berenbaum and Snyder, 1995;Dittmann et al., 1990;Ehrhardt and Baker, 1974;Frisén et al., 2009;Hall et al., 2004;Meyer-Bahlburg et al., 2004;Meyer-Bahlburg et al., 2006;Pasterski et al., 2011;Servin et al., 2003;however, see Berenbaum and Snyder, 1995;Hines and Kaufman, 1994) and increased interest in boys as playmates (Dittmann et al., 1990;Ehrhardt and Baker, 1974;Hines and Kaufman, 1994;Meyer-Bahlburg et al., 2006;Pasterski et al., 2011;Servin et al., 2003; although see Berenbaum and Snyder, 1995;Dittmann et al., 1990). ...
... Children were videotaped in a single play session using a digital camera. Toys were selected for use in the study based on prior research indicating that they showed the expected sex differences (Berenbaum and Hines, 1992;Pasterski et al., 2005). There were five female-typical toys (a Barbie doll with accessories, an infant doll with accessories, a Barbie styling head with hairstyling accessories, a tea set, and a fairy princess costume with accessories), five male-typical toys (an Action Man doll with accessories, a toy sports car, a toy army tank with accessories, a pirate costume with accessories, and a toy gun), and three gender-neutral toys (a selection of books, a puzzle, and a sketchpad with colored pencils). ...
... Also as expected, boys with and without CAH did not differ from one another on any of the measures. These findings strengthen prior conclusions that the increased early androgen exposure experienced by girls with CAH increases their male-typical, and decreases their femaletypical, childhood gender-typed behavior, including their toy and playmate preferences (Berenbaum and Hines, 1992;Berenbaum and Snyder, 1995;Ehrhardt and Baker, 1974;Hines et al., 2004;Hines and Kaufman, 1994;Meyer-Bahlburg et al., 2004;Meyer-Bahlburg et al., 2006;Pasterski et al., 2011;Pasterski et al., 2015b;Servin et al., 2003;Slijper, 1984;Zucker et al., 1996; however, see Berenbaum and Snyder, Table 2 Means (M), standard errors (SE), results of tests for sex differences (Y t or t, as appropriate), p values from t-tests, 95% confidence intervals (CIs) for mean differences, and effect sizes (Cohen's d or Wilcox and Tian's ξ, as appropriate) for assessing sex differences in the control and outcome variables for typically developing children for whom testosterone had been measured in amniotic fluid. 1995;Dittmann et al., 1990). ...
We report findings from two studies investigating possible relations of prenatal androgen exposure to a broad measure of children's gender-typed behavior, as well as specifically to children's toy and playmate preferences. Study 1 investigated these outcomes for 43 girls and 38 boys, aged 4 to 11 years, with congenital adrenal hyperplasia (CAH, a genetic condition causing increased adrenal androgen production beginning prenatally) compared to similarly-aged, unaffected relatives (41 girls, 31 boys). The predicted sex differences were found for all of the outcome measures. Furthermore, girls with CAH showed increased male-typical and decreased female-typical behavior and toy and playmate preferences compared to unaffected girls. Study 2 investigated the relationship of amniotic fluid testosterone to gender-typed behavior and toy and playmate preferences in typically developing children (48 girls, 44 boys) aged 3 to 5 years. Although the predicted sex differences were found for all of the outcome measures, amniotic fluid testosterone was not a significant correlate, in the predicted direction, of any outcome measure for either sex. The results of study 1 provide additional support for an influence of prenatal androgen exposure on children's gender-typed behavior, including toy and playmate preferences. The results of study 2 do not, but amniotic fluid testosterone may be an insufficiently sensitive measure of early androgen exposure. A more sensitive and reliable measure of prenatal androgen exposure may be needed to consistently detect relations to later gender typed behavior in non-clinical populations.
... However, some endocrine conditions or other "experiments of nature" can provide close analogs. Girls who experienced elevated prenatal androgen levels due to congenital adrenal hyperplasia have been found to exhibit more male-typical play preferences and behaviors compared to unaffected girls (Berenbaum, Beltz, Bryk, & McHale, 2018;Berenbaum & Hines, 1992;Hines, Brook, & Conway, 2004;Meyer-Bahlburg et al., 2004;Pasterski et al., 2005). Similarly, natal males whose gender was reassigned to female in infancy due to cloacal exstrophy or penile ablation during circumcision have also been found to exhibit behavioral masculinization in comparison to typically developing girls (Diamond & Sigmundson, 1997;Reiner & Gearhart, 2004). ...
... Experimental hormonal manipulations demonstrate that early androgen action masculinizes the brain and behavior in nonhuman mammals (Thornton, Zehr, & Loose, 2009;Xu et al., 2012). Prior studies in humans show greater behavioral masculinity in individuals raised as girls who (Berenbaum et al., 2018;Berenbaum & Hines, 1992;Hines et al., 2004;Meyer-Bahlburg et al., 2004;Pasterski et al., 2005) or having male-typical prenatal endocrine profiles but male-to-female sex reassignment in infancy (Diamond & Sigmundson, 1997;Reiner & Gearhart, 2004). The present findings provide evidence that low or absent early androgen action leads to more female-typical behavioral patterns in humans. ...
Low perinatal androgens predict recalled childhood gender nonconformity in men Abstract The contributions of gonadal hormones to the development of human behavioral sex differences are subjects of intense scientific and social interest. Isolated GnRH deficiency (IGD) is a rare endocrine disorder that can reveal a possible role of early gonadal hormones. IGD is characterized by low or absent gonadal hormone production after the first trimester of gestation, but external genitalia and hence gender of rearing are concordant with chromosomal and gonadal sex. We investigated recalled childhood gender nonconformity (CGN) in men (n = 65) and women (n = 32) with IGD and typically developing men (n = 463) and women (n = 1207). Men with IGD showed elevated CGN, particularly if they also reported undescended testes at birth, a marker of low perinatal androgens. Women with IGD did not differ from typically developing women. These results indicate that early androgen exposure after the first trimester contributes to male-typical gender role behaviors in childhood. Statement of relevance Childhood gender role behaviors are among the largest human behavioral sex differences. Experiments in laboratory animals show that hormones produced by the testes contribute to sex differences in behavior, but such experiments in humans would be infeasible and unethical. We measured recalled childhood gender role behavior in typically developing individuals and in individuals with isolated GnRH deficiency (IGD). People with IGD are raised as their chromosomal and gonadal sex, but do not produce gonadal hormones after the 1st trimester of gestation. Men with IGD reported higher recalled childhood gender nonconformity, particularly if they possessed a biomarker of low testicular hormone levels during gestation. Women with and without IGD did not reliably differ. These results indicate that early exposure to testicular hormones contributes to sexually differentiated behaviors in humans.
... Whereas some studies report large, stable effects for gender-related differences in children's toy preferences (Alexander, Wilcox, & Woods, 2009;van de Beek, van Goozen, Buitelaar, & Cohen-Kettenis, 2009;Weinraub et al., 1984), others find ambiguous effects (Jacklin, Maccoby, & Dick, 1973), and still others find a mix of null and large effects (Campbell, Shirley, Heywood, & Crook, 2000;Serbin et al., 2001). Similarly, some find gender differences (i.e., different preferences in girls compared to boys), but not gender-specific preferences (i.e., a preference for same-sex over other sex toys), particularly in girls (e.g., Berenbaum & Hines, 1992), while others find both gender differences and gender-specific preferences, in both girls and boys (e.g., Pasterski et al., 2005). So, studies do not always find consistent gender effects on children's toy preferences. ...
... For example, in some studies, blocks were classified as boy-related toys (e.g., Alexander & Saenz, 2012;Benenson et al., 1997;Fagot & Patterson, 1969), and in other studies they were classified as neutral toys (e.g., Cherney et al., 2003;Guinn, 1984;Wood, Desmarais, & Gugula, 2002). Similarly, drawing toys were sometimes categorized as girl-related toys (e.g., Berenbaum & Hines, 1992;Martin et al., 2013), and sometimes as neutral toys (e.g., Berenbaum & Snyder, 1995;Pasterski et al., 2005); and stuffed toys were equally likely to be classified as girl-related toys (e.g., DeLucia, 1963;Jacklin et al., 1973) as neutral toys (e.g., Alexander & Saenz, 2012;Idle et al., 1993;Moller & Serbin, 1996), but were also sometimes classified as boy-related toys (e.g., Stagnitti, Rodger, & Clarke, 1997). This pattern suggests that researchers sometimes disagree on what toys are boy-related, girl-related, or neutral. ...
It is generally recognized that there are gender-related differences in children’s toy preferences. However, the magnitude of these differences has not been firmly established. Furthermore, not all studies of gender-related toy preferences find significant gender differences. These inconsistent findings could result from using different toys or methods to measure toy preferences or from studying children of different ages. Our systematic review and meta-analysis combined 113 effect sizes from 75 studies to estimate the magnitude of gender-related differences in toy preferences. We also assessed the impact of using different toys or methods to assess these differences, as well as the effect of age on gender-related toy preferences. Boys preferred boy-related toys more than girls did, and girls preferred girl-related toys more than boys did. These differences were large (d ≥ 1.60). Girls also preferred toys that researchers classified as neutral more than boys did (d = 0.29). Preferences for gender-typical over gender-atypical toys were also large and significant (d ≥ 1.20), and girls and boys showed gender-related differences of similar magnitude. When only dolls and vehicles were considered, within-sex differences were even larger and of comparable size for boys and girls. Researchers sometimes misclassified toys, perhaps contributing to an apparent gender difference in preference for neutral toys. Forced choice methods produced larger gender-related differences than other methods, and gender-related differences increased with age.
... In humans, consistent evidence suggests that androgen exposure during early life also influences gender/sex-typed toy and activity interests, sexual orientation, gender identity, and some, though not all, gender/sex-related personality characteristics (Berenbaum & Hines, 1992;Hines, 2011Hines, , 2015Hines, Golombok, Rust, Johnston, & Golding, 2002;Nordenström, Servin, Bohlin, Larsson, & Wedell, 2002). However, evidence for an influence of early androgen exposure on human cognition, particularly spatial abilities, has been less consistent (Hines, Constantinescu, & Spencer, 2015). ...
... Our results failing to support enhancement of spatial skills by androgens during prenatal development diverge from findings in some other behavioral domains that show increased male-typical characteristics for females with CAH. These have been observed, for example, in childhood play, sexual orientation, gender identity and some personality traits (Berenbaum & Hines, 1992;Hines, 2011;Hines et al., 2002;Nordenstrom et al., 2002). Of note, however, the gender/sex difference for spatial abilities is smaller in magnitude than for these other domains Voyer et al., 1995), potentially reducing the power for detecting effects. ...
Spatial abilities contribute to life and occupational competencies, and certain spatial skills differ, on average, between males and females, typically favoring males when differences occur. Factors contributing to spatial skills could include prenatal as well as experiential/cultural influences, with biological and social influences likely interacting and difficult to disentangle. This meta-analysis examined the potential influence of prenatal androgen exposure on spatial skill by examining studies of patients with congenital adrenal hyperplasia (CAH). CAH involves elevated adrenal androgens prenatally, with overall androgen concentrations higher for females with CAH versus same-sex controls but with little overall difference between males with CAH versus controls. We hypothesized that, if androgens contribute prenatally to neurobehavioral development in humans as in many other species, females with CAH would show spatial enhancement versus control females, but with no definitive hypothesis for males. Meta-analysis of 12 studies examining overall spatial skill and three spatial subcategories failed to support enhanced spatial performance for females with CAH; males with CAH showed lower spatial ability compared to control males, at least for the category of overall spatial skill. Although statistical logic precludes accepting the null hypothesis for females, the meta-analysis failed to support the idea that prenatal exposure to androgens explains spatial gender/sex differences in humans. Alternative explanations for average gender/sex differences in some spatial tasks could include androgen exposure at other times, such as mini-puberty, or different social factors experienced by males and females. We also discuss possible explanations for the different outcomes seen in females versus males with CAH.
... Interesting observations come from studies conducted on intersex individuals. This sample represents a unique model to assess if and how sex hormones may interfere with the establishment of sex differences with a particular regard to sexual orientation and gender identity [72][73][74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89]. Comparing women with congenital adrenal hyperplasia (CAH) to female controls, more crossgender typical role behaviour and patterns during childhood [72][73][74][75][76] with a preference for typically male toys [72,74,[77][78][79][80][81] and playmates [81,88] was reported. ...
... This sample represents a unique model to assess if and how sex hormones may interfere with the establishment of sex differences with a particular regard to sexual orientation and gender identity [72][73][74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89]. Comparing women with congenital adrenal hyperplasia (CAH) to female controls, more crossgender typical role behaviour and patterns during childhood [72][73][74][75][76] with a preference for typically male toys [72,74,[77][78][79][80][81] and playmates [81,88] was reported. Additionally, other studies showed a delay of sexual experiences, lower maternalism and higher prevalence of bi-or homosexual orientation in women with CAH compared to the general female population [80,82]. ...
The complex process of sexual differentiation is known to be influenced by biological and environmental determinants. The present review has the aim of summarizing the most relevant studies on the biological basis of sexual development, and in particular, it focuses on the impact of sex hormones and genetic background on the development of sexual differentiation and gender identity. The authors conducted a search of published studies on Medline (from January 1948 to December 2019). The evidence suggests that the sexual dimorphic brain could be the anatomical substrate of psychosexual development, on which gonadal hormones may have a shaping role during prenatal and pubertal periods. Additionally, according to several heritability studies, genetic components may have a role, but a promising candidate gene has not been identified. Even though growing evidence underlines the primary role of biological factors on psychosexual development, further studies are necessary to better explain their complex interactions.
... If androgens influence behavior by shaping brain development directly, then among individuals raised as girls, those exposed to elevated androgens during their early development should exhibit more masculine behavior. In fact, girls who experienced elevated prenatal androgen levels due to congenital adrenal hyperplasia have been found to exhibit more male-typical play preferences and behaviors compared to unaffected girls [18][19][20][21][22] . Similarly, natal males whose gender was reassigned to female in infancy due to cloacal exstrophy or penile ablation during circumcision have also been found to exhibit behavioral masculinization in comparison to typically developing girls 23,24 . ...
... Experimental hormonal manipulations demonstrate that early androgen action masculinizes the brain and behavior in nonhuman mammals 16 . Prior studies in humans show greater behavioral masculinity in individuals raised as girls who experienced elevated perinatal androgens due to congenital adrenal hyperplasia [18][19][20][21][22] or having male-typical prenatal endocrine profiles but male-to-female sex reassignment in infancy 23,24 . The present findings of reduced behavioral masculinity in males with low perinatal androgens due to IGD adds complementary evidence that early androgen action promotes male-typical behavioral patterns in humans. ...
The contributions of gender socialization and direct hormonal action on the brain in the development of human behavioral sex differences are subjects of intense scientific and social interest. Prior research indicates masculinized behavioral patterns in individuals with high prenatal androgen exposure raised as girls, but complementary evidence regarding individuals with low prenatal androgens raised as boys is critically lacking. We investigated recalled childhood gender nonconformity (CGN) in men (n = 65) and women (n = 32) with isolated GnRH deficiency (IGD) and typically developing men (n = 463) and women (n = 1207). IGD is characterized by low or absent gonadal hormone production after the first trimester of gestation until hormone replacement therapy initiation around the time of puberty, but external appearance is concordant with chromosomal and gonadal sex. Compared to typically developing men, men with IGD reported higher CGN, particularly if they also reported cryptorchidism at birth, a marker of low perinatal androgens. Women with IGD did not differ from typically developing women. These results suggest that early androgen exposure after the first trimester contributes to male-typical gender role behaviors in childhood.
... There are robust evidence that interest for male-typical toys and playful activities, such as toy cars and rough-and-tumble play, are associated to a prenatal higher exposition to androgens, mainly testosterone (e.g. Auyeung et al., 2009;Berenbaum & Hines, 1992;Hines et al., 2015;Meyer-Bahlburg et al., 2004). ...
Despite their similarity with play, games are theorized as voluntary attempts to overcome unnecessary obstacles following self-handicapping arbitrary rules. These forms of entertainment are universal, usually played by adults, and have robust cross-cultural gender differences, but have received little attention from evolutionary theories. Two evolutionary hypotheses have tried to explain why adults play: to select mates and to compete for resources/status. This way, our goal was to investigate the relationship between gaming propensity, measured through Gaming Investment, and variables related to mating and status-gaining. To do so, we surveyed 1470 Brazilian adults about their gaming habits, sociodemographic data and playfulness (OLIW scale). Then, we used linear regressions and path analyses to investigate possible predictors of Gaming Investment. Results point out that Gaming Investment is related to status-seeking in gamers’ communities, meanwhile it shows no strong evidences that gaming may attract more mates or that it is related to playfulness. Therefore, gaming propensity may have evolved as a non-lethal competition for status. Modern issues may have impacted the results and are discussed suggestions for future studies.
... Há robustas evidências de que o interesse por brinquedos e brincadeiras tipicamente masculinos, como carrinhos e brincadeiras turbulentas, estão associados a maior exposição prénatal a hormônios sexuais masculinos (ex.: Auyeung et al., 2009;Berenbaum & Hines, 1992;Hines et al., 2015;Meyer-Bahlburg et al., 2004). Atualmente, as mulheres estão jogando mais que no passado Curran, 2011;Sioux Group, 2020). ...
Apesar das semelhanças com brincadeiras, jogos são teorizados como tentativas voluntárias de superar obstáculos desnecessários seguindo regras arbitrárias autodebilitantes. Essas formas de entretenimento são ubíquas, normalmente realizadas por adultos e têm robustas diferenças de gênero transculturais, mas foram pouco consideradas pelas teorias evolucionistas. Duas hipóteses evolucionistas têm tentado explicar por que adultos jogam: para selecionar parceiros e para competir por recursos/status. Assim sendo, nosso objetivo foi investigar a relação entre a propensão para jogar, medida pelo Investimento em Jogos, e variáveis associadas à obtenção de parceiros e de status. Para isso, um questionário foi aplicado a 1470 adultos brasileiros perguntando sobre seus hábitos de jogo, informações sociodemográficas e a escala OLIW. Ao todo, foram obtidas 939 respostas válidas aqui analisadas. Usamos regressões lineares e uma análise de caminho para investigar possíveis preditores de investimento em jogos. Os resultados apontam que investir em jogos está associado a busca por status nas comunidades de jogadores, mas não encontrou fortes evidências de que jogos atraiam mais parceiros ou estejam relacionados à personalidade brincalhona. Assim, a propensão para jogar pode ter evoluído como uma competição não-letal por status. Questões contemporâneas podem ter impactado os resultados e são discutidas sugestões para futuros estudos.
... Studies of individuals with CAH may shed light on the brain organization theory, and advocates of this theory will attribute atypical psychosexuality in this group to elevated prenatal androgen levels that have masculinized the brain. Prenatal elevated androgen levels have also been shown to influence children's sex-typical play behaviors (Dittmann et al., 1990;Berenbaum and Hines, 1992;Hall et al., 2004;Hines et al., 2004;Hines, 2006), which may explain why females with CAH have been shown to demonstrate more male-typical rough and "tomboyish" behavior than controls. Evidence exists to link childhood play interests and adult sex orientation (Saghir, 1973;Bell and Hammersmith, 1981;Grellert et al., 1982;Harry, 1982;Bailey and Zucker, 1995). ...
Congenital adrenal hyperplasia (CAH) is a genetic condition of the steroidogenic enzymes in the adrenal cortex normally leading to variable degrees of cortisol and aldosterone deficiency as well as androgen excess. Exposure to androgens prenatally might lead to ambiguous genitalia. The fetal brain develops in traditional male direction through a direct action of androgens on the developing nerve cells, or in the traditional female direction in the absence of androgens. This may indicate that sexual development, including sexual orientation, are programmed into our brain structures prenatally. The objective of this study was to perform a systematic review of the literature, investigating sexual orientation in individuals with CAH. The study also aimed at identifying which measures are used to define sexual orientation across studies. The review is based on articles identified through a comprehensive search of the OVIDMedline, PsycINFO, CINAHL, and Web of Science databases published up to May 2019. All peer-reviewed articles investigating sexual orientation in people with CAH were included. Quantitative, qualitative, and mixed methods were considered, as well as self-, parent-, and third-party reports, and no age or language restrictions were enforced on publications. The present review included 30 studies investigating sexual orientation in patients with CAH assigned female at birth (46, XX) (n = 927) or assigned male at birth (46, XY and 46, XX) (n = 274). Results indicate that assigned females at birth (46, XX) with CAH had a greater likelihood to not have an exclusively heterosexual orientation than females from the general population, whereas no assigned males at birth (46, XY or 46, XX) with CAH identified themselves as non-heterosexual. There was a wide diversity in measures used and a preference for unvalidated and self-constructed interviews. Hence, the results need to be interpreted with caution. Methodological weaknesses might have led to non-heterosexual orientation being overestimated or underestimated. The methodological challenges identified by this review should be further investigated in future studies.
... Following from this, early prenatal effects of sex hormones have been suggested to impact sex-typed preferences in children (for a review, see Berenbaum & Beltz, 2016). For example, girls with congenital 1 3 adrenal hyperplasia (CAH) who are exposed to high levels of androgens prenatally and in the early postnatal period show more male-typical play behavior than unaffected controls (Berenbaum & Hines, 1992;Nordenström, Servin, Bohlin, Larsson, & Wedell, 2002;Pasterski et al., 2005) and parents describe their daughters behavior as more masculine in comparison with unaffected female relatives (Hines, 2003). Additionally, women with CAH retrospectively describe their play behavior as more masculine (Hines, Brook, & Conway, 2004). ...
Sex-typed play behavior shows large sex differences and seems to be affected by prenatal sex hormones. For example, a smaller, more male-typical ratio between the second and fourth digit length (2D:4D), a proposed marker for prenatal testosterone exposure, has been shown to be related to sex-typed play preference in childhood. Nevertheless, it is still being debated whether 2D:4D displays a stable sex difference throughout childhood, as there are few longitudinal studies. In the present study, children’s 2D:4D was measured on both hands on four occasions from early infancy to early childhood (T1: 5 months, T2: 9 months, T3: 20 months, and T4: 40 months) providing the rare possibility to test the temporal stability of the sex difference. Parents completed the Preschool Activities Inventory at T4 and reported on the number of older brothers and sisters as a measure for socialization influences. Parents described boys as playing more masculine and less feminine than girls. Boys had smaller 2D:4D than girls at all measurements (T1–T4) and on both hands (right/left). Nevertheless, 2D:4D increased significantly from T3 to T4 in both sexes. Girls, but not boys, who were described as playing more masculine and less feminine had more masculine 2D:4D ratios at T1–T4 on both hands (except for right 2D:4D at T2 and T3) and had more older brothers and fewer older sisters. These data underline the stability of the sex difference in 2D:4D and show the importance of both biological and social influences on sex-typed play behavior.
... In baby girls, it is the other way around. This is an innate, evolved preference(Alexander & Hines, 2002;Berenbaum & Hines, 1992;Hassett et al., 2008; Kimura, 1999; meta-analysis byPuts et al., 2008); ...
Evolutionary Psychology is in line with evolutionary biology and offers testable hypotheses and retrodic- tions. EP has become a multidisciplinary research domain, gathering the brightest re- searchers from different fields of study, including biology, anthropology, medicine, and psychology. Evolutionary psychology provides new ways of thinking about literally every topic in psychology and thus can be used as a framework to serve as a first test for midlevel or mini theories.
If we really want to know how our psychology works, we need to study biology and the in- teraction of biology with our environment, just as biologists need to know chemistry and physics. Understanding human nature better will help us find strategies to counter phe- nomena we dislike such as warfare, racial or sexual discrimination, workplace bullying, unsound internal competition reducing the beneficial outputs of collaboration, etc.
... Firstly, girls suffering from congenital adrenal hyperplasia (CAH) are exposed in utero to abnormally high levels of androgens that masculinize their genital structures. Even if their endocrine condition is normalized by pharmacological means, their genital morphology is surgically "corrected" soon after birth and they are subsequently raised as girls, these girls will later on demonstrate masculinization of a variety of behavioral traits (e.g., aggressive play and toy selection) (Berenbaum, 1999;Berenbaum and Hines, 1992;Hines, 2004Hines, , 2006. They will also display a significantly increased incidence of homosexual (or at least not strictly heterosexual) orientation (up to 40 % compared to less than 10 % in control populations; See Fig. 2 (Hines, 2006;Meyer-Bahlburg et al., 2008;Money et al., 1984). ...
BALTHAZART J. Sex partner preference in animals and humans. NEUROSCI BIOBEHV REV XX (Y) ZZZ-KKK, 2020. aaaaaaaaaa
Sex differences in brain and behavior of animals including humans result from an interaction between biological and environmental influences. This is also true for the differences between men and women concerning sexual orientation. Sexual differentiation is mediated by three groups of biological mechanisms: early actions of sex steroids, more direct actions of sex-specific genes not mediated by gonadal sex steroids and epigenetic mechanisms. Differential interactions with parents and conspecifics have additionally long-term influences on behavior. This presentation reviews available evidence indicating that these different mechanisms play a significant role in the control of sexual partner preference in animals and humans, in other words the homosexual versus heterosexual orientation. Clinical and epidemiological studies of phenotypically selected populations indicate that early actions of hormones and genetic factors clearly contribute to the determination of sexual orientation. The maternal embryonic environment also modifies the incidence of male homosexuality via immunological mechanisms. The relative contribution of each of these mechanisms remains however to be determined.
... Finally, the present research examined sex differences in childhood play preferences. A large number of studies, using a variety of measures and a broad range of toys and play activities, have consistently found differences in boys' and girls' play preferences in preschool age, and across childhood (Berenbaum and Hines, 1992;Etaugh and Liss, 1992;Grellert et al., 1982; also see reviews by Collaer & Hines, 1995, Todd et al., 2018Zosuls and Ruble, 2018). The common finding was that girls tend to prefer dolls, dolls' accessories, and stuffed animals, whereas boys tend to prefer games that involve spatial manipulation and construction such as tools, blocks, and transportation toys (Bradbard and Parkman, 1984;Emmott, 1985;Erikson, 1951;Kersh et al., 2008;Serbin and Connor, 1979). ...
Our research explored the structure of childhood visual play preferences, and examined different types of visual play in relation to individual differences in visualization and aptitudes in academic specializations requiring visualization skills. Principal component analysis dissociated visual-object play (e.g., exploring drawing media or decorative crafts) from visual-spatial play (e.g., assembling and disassembling mechanisms or playing with construction toys) preferences. Moreover, visual play preferences were dissociated from verbal play preferences (e.g., vocabulary games or making up stories). The structure of visual play preferences was consistent with object and spatial dimensions of individual differences in visualization. Visual-object and visual-spatial dimensions of play preferences were differentially related to measures of object visualization (processing pictorial appearances in terms of shape, texture, and color) versus spatial visualization (processing spatial relationships and spatial manipulations), as well as to aptitudes in artistic versus scientific domains. Furthermore, our research sheds new light on sex differences in play behavior: Previous studies commonly associated gender-specific play with visual versus verbal-social processing; our research demonstrated sex differences in play preferences across the two dimensions of visual play, where females preferred visual-object and males preferred visual-spatial play. Moreover, we found the object vs. spatial structure of visual play preferences was largely the same in both sexes, suggesting that differences in visual play preferences cannot be reduced to sex differences. Also, our questionnaire assessing visual-object, visual-spatial and verbal play preferences, developed for research purposes, demonstrated good reliability. Its two scales, assessing visual-object and visual-spatial play preferences, discriminatively correlated with assessments of individual differences in object and spatial visualization, respectively. This research creates a basis for further creation of comprehensive measures of visual play preferences, and should stimulate future studies examining visual play preferences and how they may create developmental opportunities for skills and preferences lasting into adulthood.
... The first sets of evidence across ages and species suggest some role for biological/hormonal differences between males and females that contribute to early gender-specific toy preferences. Prenatal sex hormones have been shown to modify sex-dimorphic behavior and temperamental sex differences (Ehrhardt & Meyer-Bahlburg, 1981), and human androgen levels appear to be related to gender-related toy preferences, such that high androgen level increases male toy preference among females (Berenbaum, 1999;Berenbaum & Hines, 1992;Hines & Kaufman, 1994). Similarly, infants' testosterone levels before 6 months were associated with their gender-typed behavior at 14 months (Lamminmäki et al., 2012). ...
In contrast to the anecdotal claim that “male infants like cars and female infants like dolls,” previous studies have reported mixed findings for gender‐related toy preferences in infancy. In Experiment 1, we explored the emergence of gender‐related preferences using face–car pairs (Experiment 1a, n = 51, 6–20 months) or face–stove pairs (Experiment 1b, n = 54, 6–20 months). In Experiment 2 (n = 42, 14–16 months), we explore the effect of toy properties, infants' past toy exposure, activity levels, and parental attitudes on such preferences using a wider range of toys. For both studies, infants demonstrated a general preference for faced stimuli over other objects, except for male infants who showed no preference between dolls and cars at around 15 months. Infants' prior experience participating in motor‐intensive activities, with wheeled toys and parental attitudes appeared to relate to female infants' preferences for dynamic toys. These results indicate a range of factors influence gendered toy preferences and suggest that nurture plays an important role.
... Repeated evidence of infants' preference for gender-typical toys (i.e., plush toys are considered feminine and moving toys, such as trucks, are considered masculine) demonstrates that some sensitivity to social norms is present within the first year of life (Jadva, Hines, & Golombok, 2010;Lauer, Udelson, Jeon, & Lourenco, 2015;Serbin, Poulin Dubois, Colburne, Sen, & Eichstedt, 2001; for a review, see Todd et al., 2017). The fact that young infants prefer gender-typical toys has been taken as evidence that preferences for gender-typical toys (or at least some confounded feature, such as softness) may be on some level biologically hardwired possibly via prenatal androgen exposure (Berenbaum & Hines, 1992). Further support for this claim comes from demonstrations that various species of non-human primates also exhibit gender-typical toy preferences, which some authors suggest indicates that such preferences emerged early in our evolutionary history (Alexander & Hines, 2002;Hassett, Siebert, & Wallen, 2008). ...
The waist‐to‐hip ratio (WHR) is correlated with health and associated with sex, attractiveness, and age judgments by adults. We examined the development of sensitivity to the WHR by testing 3.5‐month‐old infants' (N = 71) preference between images depicting different WHRs. Female 3.5‐month‐olds exhibited a preference for the WHR associated with attractiveness and mate value by adults (0.7) over a larger WHR (0.9). This preference was exhibited when infants were tested on upright stimuli but not when they were tested on inverted stimuli, indicating that low‐level differences (e.g., curviness) were not driving performance. This sensitivity to WHR may lay the foundation for more explicit preferences and categorical associations later in life. In contrast to females, male infants failed to exhibit a significant preference for the 0.7 WHR in either orientation, replicating previous findings of female infants' superior processing of social stimuli. Implications for theories of the development of body knowledge and sex differences in social information processing are discussed. Waist‐to‐hip ratio (WHR) is a significant social cue for adults, with 0.7 WHR considered ideal for females. 3.5‐month‐old female infants preferred 0.7 WHR over 0.9 WHR, but male infants did not exhibit a preference. Findings indicate sensitivity to WHR early in life and replicate prior findings of female infants' superior processing of social stimuli.
... Pediatric endocrinology offers another distinct line of evidence that also utilizes children samples. Girls diagnosed with congenital adrenal hyperplasia, a masculinizing endocrinological condition, hold more masculinized toy preferences than girls unafflicted with this condition (Berenbaum and Hines, 1992;Nordenström et al., 2002). ...
Many detractors of evolutionary psychology (EP) presume that adaptive arguments are nothing more than whimsical and unfalsifiable just-so stories. The reality though is that the epistemology of EP is precisely the opposite of this antiquated canard in that it fixes the evidentiary threshold much higher than is typically achieved by most scientists. EP amasses evidence across cultures, time periods, disciplines, paradigms, methodologies, and units of analyses in validating a given scientific explanation. These nomological networks of cumulative evidence stimulate greater interdisciplinarity, lesser methodological myopia, and increased consilience (unity of knowledge). A component in building such nomological networks is to examine phenomena that are cross-culturally invariant (human universals) versus those that vary cross-culturally as adaptive responses (the domain of behavioral ecologists and gene-culture coevolution modelers). The epistemological efficacy of this unique approach is highlighted using two cases studies, the sex-specificity of toy preferences and men's preference for the hourglass figure.
... Furthermore, some endocrinological disorders can reshape children's predisposition in toy preference. (Berenbaum & Hines, 1992;Hönekopp & Thierfelder, 2009). ...
... Indeed, manipulating androgens prenatally in non-human primates alters brain regions and behaviors (98). Many studies have been performed in girls prenatally exposed to high levels of androgens because of congenital adrenal hyperplasia (CAH) where there is strong evidence of male typical play behavior, suggesting a similar hormonal influence on human brain development (98)(99)(100)(101)(102)(103)(104). This influence of androgen levels on the brain has been identified not only among affected girls but also in the general population. ...
Hypothalamic-pituitary-gonadal (HPG) axis activation occurs three times in life: the first is during fetal life, and has a crucial role in sex determination, the second time is during the first postnatal months of life, and the third is with the onset of puberty. These windows of activation recall the three windows of the “Developmental Origin of Health and Disease” (DOHaD) paradigm and may play a substantial role in several aspects of human development, such as growth, behavior, and neurodevelopment. From the second trimester of pregnancy there is a peak in gonadotropin levels, followed by a decrease toward term and complete suppression at birth. This is due to the negative feedback of placental estrogens. Studies have shown that in this prenatal HPG axis activation, gonadotropin levels display a sex-related pattern which plays a crucial role in sex differentiation of internal and external genitalia. Soon after birth, there is a new increase in LH, FSH, and sex hormone concentrations, both in males and females, due to HPG re-activation. This postnatal activation is known as “minipuberty.” The HPG axis activity in infancy demonstrates a pulsatile pattern with hormone levels similar to those of true puberty. We review the studies on the changes of these hormones in infancy and their influence on several aspects of future development, from linear growth to fertility and neurobehavior.
Hintergrund und Ziele: Der Konsum von Alkohol und alkoholassoziierte Erkrankungen gehören weltweit neben Bluthochdruck und Rauchen zu den häufigsten Todesursachen. Die gesundheitlichen, sozialen und finanziellen Konsequenzen für die Betroffenen, deren Angehörige und die Gesellschaft insgesamt sind potenziell vermeidbar, weswegen die Suche nach Risikofaktoren und die rechtzeitige Einleitung wirkungsvoller Präventionsmaßnahmen entscheidend sind. Aus den zahlreichen möglichen Einflussfaktoren wurden im Rahmen dieser Studie die Wirkung von pränatalen und von aktuell zirkulierenden Sexualhormonkonzentrationen auf die Alkoholabhängigkeit ausgewählt und die geschlechtsspezifischen Unterschieden im Trinkverhalten näher beleuchtet. Aufgrund deutlicher Parallelen zwischen der Auswirkung dieser Parameter sowohl auf die Alkoholabhängigkeit als auch auf das räumliche Vorstellungsvermögen, wurde schließlich die Frage gestellt, ob Leistungen auf dem Gebiet der mentalen Rotation als Risikomarker für die Entstehung einer Alkoholabhängigkeit genutzt werden können. Methoden: Bei 235 Kontrollen (n(♀)=102; n(♂)=133) und 153 Patienten (n(♀)=66; n(♂)=87), welche die Kriterien einer Alkoholabhängigkeit nach ICD-10-, DSM-IV- und DSM-5 erfüllten, wurde die Leistung auf dem Gebiet der mentalen Rotation anhand der revidierten Version des Mental Rotation Test (MRT) basierend auf dem Original von Vandenberg und Kuse ermittelt. Pränatale Sexualhormonkonzentrationen wurden indirekt mittels der Längenverhältnisse der Zeige- und Ringfinger (kurz 2D:4D-Fingerlängenverhältnis) und der Händigkeit bestimmt. Aktuell zirkulierende Sexualhormonkonzentrationen wurden aus Blutproben gewonnen. Das Ausmaß des Alkoholkonsums der Patienten wurde mit dem Lifetime Drinking History-Erhebungsbogen erfasst. Darüber hinaus wurde die Gruppe der gesunden Kontrollen weiter in eine Gruppe der Binge Drinker und der Non-Binge Drinker unterteilt und deren Leistung im MRT mit denen von Patienten verglichen. Ergebnisse und Beobachtungen: Die Patienten- und Kontrollgruppe unterschieden sich nicht hinsichtlich der Geschlechterverteilung und des Alters. Die Gruppe der Kontrollen verfügte über signifikant mehr Bildungsjahre als die Gruppe der Patienten (p<0,001). Die höhere Anzahl an Bildungsjahren hatte in der Kontrollgruppe einen signifikant positiven Einfluss auf den MRT (p=0,022). Das Alter beeinflusste sowohl in der männlichen (p<0,001) und in der weiblichen (p<0,001) Kontrollgruppe als auch bei Frauen der Patientengruppe (p=0,009) die Leistung im MRT negativ. Innerhalb der Patientengruppe tranken die Frauen seit Beginn der Abhängigkeit signifikant weniger Alkohol pro Tag als die Männer (p<0,001). Auch lag die Gesamtmenge an konsumiertem Alkohol bei Patientinnen signifikant unter dem der männlichen Patienten (p<0,001). Männer erreichten nicht nur in der Kontrollgruppe (p<0,001), sondern auch in der Patientengruppe (p=0,001) signifikant höhere Ergebnisse im MRT als weibliche Studienteilnehmer der entsprechenden Gruppen. Die weibliche (p=0,026) und männliche (p<0,001) Kontrollgruppe schnitt im MRT signifikant besser ab als die entsprechenden Teilnehmer der Patientengruppe. Binge Drinker erzielten im Vergleich zu Patienten und Non-Binge Drinkern im Durchschnitt die besten Ergebnisse. Das 2D:4D-Fingerlängenverhältnis und die Händigkeit zeigten in keiner der Gruppen einen signifikanten Zusammenhang mit der erreichten Punktzahl im MRT. Aktuelle bioverfügbare Testosteron- (p=0,012), Dihydrotestosteron- (p<0,001) und Progesteronkonzentrationen (p=0,010) korrelierten bei Männern der Kontrollgruppe, die Dihydrotestosteron -Konzentration (p=0,012) korrelierte bei Frauen der Kontrollgruppe signifikant positiv mit dem Ergebnis des MRT. Die Anzahl an stationären Entwöhnungen korrelierte in der Patientengruppe signifikant positiv mit der Leistung im MRT (p=0,004). Praktische Schlussfolgerungen: Entgegen der Hypothese erzielten die Patienten und Patientinnen deutlich schlechtere Ergebnisse im Mental Rotation Test als die gesunden Kontrollgruppen, was hauptsächlich auf die alkoholbedingte Neurodegeneration zurückgeführt werden kann. Aufgrund des fehlenden Zusammenhangs zwischen der mentalen Rotation und den Markern für pränatale Androgene, dem 2D:4D-Fingerlängenverhältnis und der Händigkeit, kann geschlussfolgert werden, dass letztendlich eher eine schwächere Wechselbeziehung zwischen dem 2D:4D-Fingerlängenverhältnis, der Händigkeit und dem MRT besteht als zwischen dem 2D:4D-Fingerlängenverhältnis, der Händigkeit und dem Risiko einer Alkoholabhängigkeit. Die Subgruppe der Binge Drinker erreichte im Durchschnitt die besten Ergebnisse im MRT, was den Grundgedanken dieser Forschungsarbeit stützt, da Binge Drinker tendenziell ein kleineres 2D:4D-Fingerlängenverhältnis aufweisen als gesunde Kontrollen und gleichzeitig gesunde Kontrollen auf dem Gebiet der mentalen Rotation übertreffen. Hypothesenkonform konnte ein positiver Einfluss aktuell zirkulierender Androgenkonzentrationen, hier vor allem des Dihydrotestosterons, auf die mentale Rotation in der Kontrollgruppe beobachtet werden kann. Der Mental Rotation Test ist folglich bei bereits bestehender Alkoholabhängigkeit nicht als Risikomarker geeignet, da die potentielle kognitive Leistung der Probanden aufgrund der Substanzmissbrauchsstörung nicht sicher erfasst werden kann. Zur Beantwortung der zugrunde liegenden Studienfrage wären prospektive Längsschnittstudien notwendig, bei der die kognitive Leistungsfähigkeit vor Entwicklung einer Abhängigkeit erfasst wird, um eine Verzerrung der Ergebnisse durch alkoholbedingte neurodegenerative Effekte zu vermeiden.
Human gender-related behavior/psychology is shaped by a developmental system that involves numerous influences interacting over time. Understanding of the full range of elements in the system and how they interact is currently incomplete. The available evidence suggests, however, that early exposure to testosterone, postnatal socialization, e.g., by parents and peers, and self-socialization related to cognitive understanding of gender are important elements. This article focuses on prenatal and early neonatal influences of testosterone on gender-related psychological/behavioral outcomes, and contextualizes these hormonal influences within an understanding of socialization influences. There is consistent evidence that early testosterone exposure influences childhood gender role behavior, including sex-typical toy play, as well as gender identity and sexual orientation. Evidence for similar hormonal influences on spatial ability and on traits related to autism, or autistic spectrum disorder, is inconsistent. Evidence from girls exposed to elevated testosterone prenatally suggests that they experience alterations in processes of external socialization, as well as self-socialization, and that these, along with early testosterone exposure, shape gender-related outcomes.
Prenatal hormones have been proposed as key factors impacting child development as well as long-term health and disease. Digit ratio (the ratio of the lengths of the second to fourth digits; 2D:4D) has been proposed as a sexually dimorphic, noninvasive marker of prenatal androgen exposure that can be reliably measured in children and adults. To date, few longitudinal pregnancy cohort studies have examined childhood digit ratio in relation to other relevant measures including prenatal hormones and androgen-sensitive outcomes. To augment the current literature on this topic, we measured right-hand digit ratio in 4-year-old children participating in The Infant Development and the Environment Study, a multicenter longitudinal cohort study that has been following mother–child dyads since the first trimester of pregnancy ( n = 321). We assessed sex differences in digit ratio and fit multivariable linear regression models to examine digit ratio in relation to: (1) child sex; (2) maternal sex steroid hormone concentrations in early pregnancy; (3) newborn anogenital distance, another proposed measure of sensitivity to prenatal androgens; and (4) gender-typical play behavior as measured by the Preschool Activities Inventory (PSAI) at age 4. We observed no sex difference in digit ratio; the mean 2D:4D was 0.97 ± 0.05 mm in both sexes. Furthermore, digit ratio was not associated with maternal sex steroid concentrations in early pregnancy, anogenital distance in either sex, or PSAI scores in either sex in covariate-adjusted models. In conclusion, we observed no evidence that early childhood digit ratio was associated with child sex or hormone-sensitive measures in this cohort.
A growing body of evidence supports a potential link between autism spectrum disorder (ASD) and gender dysphoria, yet few studies have looked at sex differences in the co‐occurrence of gender diversity and ASD. The aim of this study was to characterize sex differences in gender‐diverse expressions and identities, as well as gender‐related concerns, in youth with ASD. Parents of youth with ASD ages 6–21 (n = 163) completed an online questionnaire about their child's gender expression and identity. Sex‐typed behaviors during childhood were measured using the Gender Identity Questionnaire (GIQ). Semi‐partial Kendall correlations and chi‐square tests were used to compare gender non‐conformity, gender‐diverse identities, and gender‐related concerns between sexes. Sex‐based differences in mean GIQ score and individual GIQ items were evaluated using a linear regression and semi‐partial Kendall correlations, respectively. All regressions and correlations controlled for child age. Parents of girls were more likely to report child appearances and mannerisms that were less concordant with their child's birth sex. Based on parent‐report, girls had lower mean GIQ scores, indicating greater cross‐gendered/fewer same‐gendered behaviors in childhood. Lastly, parents of girls with ASD were more likely to report that their daughters experienced anxiety due to gender‐related concerns and discomfort during puberty than parents of boys. These findings suggest that girls with ASD seem more likely have gender‐diverse preferences, mannerisms, and appearances that fall outside of traditional gender norms. Gender‐related concerns appear to be a source of real distress in girls with ASD, highlighting the need for individualized support, especially during puberty.
Lay Summary
Despite evidence of a potential link between autism and gender diversity, few studies have explored differences in gender identity/expression between boys and girls with autism. Based on parent responses, we found that girls with autism are more likely than boys to have appearances and mannerisms, as well as behaviors during childhood, that fall outside of the traditional gender role. The unique profile of girls with autism and their elevated distress over gender‐related concerns call for individualized support during adolescence.
Background:
We report data of a Belgian observational prospective cohort study regarding cognitive and behavioural development until the age of 36 months in relation to internal exposure to organochlorine pollutants [sum of polychlorinated biphenyls (sum PCB), dioxin-like activity, PCB118, PCB170, hexachlorobenzene (HCB) and p,p'-dichlorodiphenyldichloroethylene (DDE)] measured in cord blood.
Methods:
Participants were recruited as part of an Flemish Environmental Health Survey (2002-2006). Two hundred and six mother-child pairs were recruited. Hundred twenty five toddlers [Reynell Taal Ontwikkelings Schalen (language development, RTOS), Snijders-Oomen Niet-verbale intelligentietest (non-verbal intelligence, SON), Bayley Scales, milestones, Infant Behaviour Questionnaire (IBQ), gender specific play behaviour, Neurobehavioral Evaluation System (NES)-attentional task] and their mothers [Home Observation Measurement of the Environment (HOME), Wechsler Abbreviated Scale of Intelligence (WASI), State-Trait Anxiety Inventory (STAI), general questionnaires] were tested. Statistical analysis was performed with the SPSS program. Much attention was paid to confounding factors.
Results:
In the first years of development, higher organochlorine pollutants were associated with less active children (delayed crawling: sum PCB*HCB (p < 0.05), sumPCB*DDE (p < 0.1); delayed first steps alone: sum PCB (p < 0.5), PCB118 (p < 0.01), PCB170 (p < 0.01), HCB (p < 0.01); less switching between toys: sum PCB (p < 0.01); less switching between toys in boys: PCB118 (p < 0.01), sum PCB(p < 0.01)). At 12 months children with higher dioxin-like activity tended to show less fear responses(p < 0.1) (IBQ 12 months). At 36 months, a slower development of language comprehension (RTOS) was related to all organochlorine exposure parameters(p < 0.1 or p < 0.05) except DDE. Lower nonverbal IQ scores (SON) were related to PCB118 in boys only(p < 0.05 or p < 0.01). Less masculine and more non-gender specific play behaviour was associated with sum PCB in boys and girls at 36 months(p < 0.1). Moreover, PCB118 (p < 0.05), PCB170 (p < 0.1), HCB(p < 0.05) and DDE(p < 0.05) were associated with diminished masculine play behaviour in boys.
Conclusion:
Our data confirm the observations that neurobehavioral development of young children is adversely influenced by environmental concentrations of PCBs, especially in boys. In this context, observation of play behaviour seems to be a reliable, easy to perform and sensitive test to detect neurotoxic effects of chemicals like PCB's and dioxin-like compounds in very young children. On the basis of our results, we hypothesize that an underarrousal pattern may play a role in the spectrum of effects measured in toddlers prenatally exposed to PCBs and dioxin-like compounds.
Background
We systematically reviewed evidence for the androgen theory which proposes exposure to elevated levels of androgens in early development predisposes to autistic behaviour.
Method
MEDLINE, EMBASE and Pubmed were searched for studies measuring androgens in mother or child during pregnancy or the first year of life and examined autistic behaviours (including social ability and repetitive behaviour) and language measured up to age 24 years.
Results
Twenty-five of 3,041 publications met inclusion criteria, exploring 11 unique cohorts. Overall quality of evidence was very low as studies were non-experimental and most had high risk of bias. Only one research group found significant associations between autistic behaviour and androgens in amniotic fluid. There were mixed findings across the studies reviewed. Meta-analysis indicated a small significant pooled association between autistic behaviour and androgens in amniotic fluid (males and females combined; 3 studies), 0.28 [95 % CI 0.14, 0.41], also significant in males and females separately.
Conclusions
Despite interest in this topic, of studies exploring direct measures of early androgens and later autistic traits, there is only a small amount of low-quality evidence from independent cohorts. The androgen theory of autism is neither confirmed nor refuted by the existing association studies included in this review.
Aim
Comparison of gender personality traits in CAH-affected 46,XX patients with those in 46,XY patients with complete androgen insensitivity syndrome (AIS) or gonadal dysgenesis (GD).
Patients and methods
Thirty-six 46,XX CAH, three 46,XY AIS, four 46, XY GD patients. The Bem Sex-Role Inventory (BSRI) was used to measure masculinity, femininity and to research gender roles.
Results
The lowest femininity values were in the patients with CAH, the highest in patients with AIS. Age at study was not associated with the value of BSRI score. CAH patients with the Prader score 4 had lower median femininity score values than those who had the Prader score 3, however, the difference was statistically insignificant.
Conclusion
More masculinizied personality behavioral traits in females with CAH most likely result from exposure of the fetal brain to high levels of androgens.
Administered a cognitive test battery that emphasized spatial ability, verbal fluency, and perceptual speed and accuracy to 17 females (aged 12.7–23.2 yrs) and 8 males (aged 13–29.9 yrs) with congenital adrenal hyperplasia (CAH) and 13 normal female relatives (aged 11.4–31.1 yrs) and 14 unaffected male relatives (aged 12.5–28.8 yrs). In addition, 13 fathers and 15 mothers of CAH patients participated. Ss also completed the Progressive Matrices, a vocabulary test, and an early life activities questionnaire (ELAQ). Findings indicate that CAH females, as compared with normal females, showed significantly enhanced performance on hidden pattern, card rotation, and mental rotation tests of spatial ability. On the ELAQ, CAH females, relative to normal females, showed significantly lower frequencies of participation in activities involving verbal expression and a trend toward greater participation in spatial manipulation activities. However, differences between CAH females and normal females in early childhood activities did not account for observed differences in spatial ability, given the absence of a significant correlation between the spatial manipulation activity scale and spatial ability. There was an absence of reliable differences between male CAH patients and controls across spatial tasks. Results are consistent with an effect of pre- and perinatal androgenizing hormones on the development of spatial ability. (58 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Explanations of sex-related differences in spatial ability emphasizing the role of sex-differentiated experience have not been supported by direct measurement of spatial activities during adolescence, the period when these differences seem to increase. The present research involved development of a scale to measure the spatial experience of adolescents and adults. In Study 1, a list, as complete as possible of adolescent activities was compiled and given to undergraduate judges for ratings of involvement of spatial skills and sex-typing. Judges also indicated whether they had participated in each activity. Activities considered spatial by 75% or more of the judges were used to develop a spatial experience questionnaire. Judgments of the spatial nature of tasks were positively correlated with judged masculinity and with greater male than female participation. In Study 2, participation in spatial activities by undergraduates was correlated with spatial ability as measured by the Differential Aptitude Test. The activity questionnaire should prove useful in studying the development of spatial ability in adolescents and adults.
A quantitative analysis of the volume of 4 cell groups in the preoptic-anterior hypothalamic area (PO-AHA) and of the supraoptic nucleus (SON) of the human brain was performed in 22 age-matched male and female individuals. We suggest the term Interstitial Nuclei of the Anterior Hypothalamus (INAH 1-4) to identify these 4 previously undescribed cell groups in the PO-AHA. While 2 INAH and the SON were not sexually dimorphic, gender-related differences were found in the other 2 cell groups. One nucleus (INAH-3) was 2.8 times larger in the male brain than in the female brain irrespective of age. The other cell group (INAH-2) was twice as large in the male brain, but also appeared to be related in women to circulating steroid hormone levels. Since the PO-AHA influences gonadotropin secretion, maternal behavior, and sexual behavior in several mammalian species, these results suggest that functional sex differences in the hypothalamus may be related to sex differences in neural structure.
In the last decade, we have experienced a small revolution in the study of the neural and hormonal bases of sex differences in behavior and reproductive function. The previous view had been that these sex differences might have an anatomical basis, but anatomical differences in neural circuits were likely to be small and subtle. This view stemmed from the observation that many behaviors typical of one sex (e.g. lordosis behavior in female rodents) could also be observed to a lesser extent in the opposite sex, as long as the proper hormonal milieu was present. Thus, both sexes must possess the neural circuitry needed for the behavior, and the quantitative (not qualitative) differences between the sexes seemed potentially explained by subtle differences in the microtopography of synaptic relations among neurons, in the metabolism of neurotransmitters, or in steroid receptor mechanisms in neurons. Today, the idea of significant structural sex differences in the CNS is accepted. We now recognize that gonadal steroids can exert profound effects on the morphogenesis and survival of specific neurons resulting in marked sex differences in CNS structure. We begin by reviewing briefly the history of this field since 1930. We then discuss at length three anatomical dimorphisms that have played a dominant role in shaping our thinking about sexual differentiation of the CNS. We compare these systems, and discuss the implications of work on each. Finally, we suggest that gonadal steroids can be used profitably as tools to perturb certain neural systems in known ways, and thus aid in our understanding of how steroids influence certain developmental processes, and increase our understanding of those processes per se.
Patients with congenital adrenal hyperplasia represent a unique opportunity to study the effects of prenatal sex hormones on the development of the brain and behavior. They also reveal the amazing capacity of people to adjust to major developmental aberrations.
In the normal male fetus a 46XY genotype leads to gonadal male sex; thereafter it is the hormones produced by the fetal testis which imprint a male pattern onto the indifferent embryonic genital precursor (Jost, 1953; Wilson, 1978). This chapter will review the changes in and regulation of fetal hormonal levels and their relation to male genital differentiation.
The effect on adult sexual behavior of high doses of progesterone and testosterone given to neonatal male rats were tested and compared with the effects of administered estrogen, cyproterone, and cyproterone acetate. Results indicated that high doses of all the test substances affect male sexual performance; the direction of change, however, is dependent upon the parameter measured.It is asserted that not only must a critical period be considered in evaluating developmental influences on sexual performance but so too must the steroidal environment in terms of type and dosage. High dosages used in the study are seen as possible experimental models of the abnormal hormonal milieu associated with certain clinical situations.
2 sets of scales were developed designed to measure the strength of sex typing in children's play patterns in a naturalistic setting. Over a 12-week observational period, the scales based upon those activities showing a sex difference in play preferences appeared to be more stable than those scales based upon adult ratings of masculine and feminine activities. Masculine and feminine activity preferences, as measured by the more stable scales, were correlated with observational measures of other classroom behavior and performance on 3 cognitive tests. These results suggested that (a) many children have already learned to avoid opposite-sex activities by the time they enter nursery school; (b) sex-role learning during the preschool period appears to involve increasing attention to same-sex activities; and (c) the development of visual-spatial ability in boys is related to involvement in masculine activities. The advantages of a behaviorally based definition of masculine and feminine activity preference are discussed.
Kindergarten children were videotaped playing with female- and male-traditional toys as well as nonsex-typed toys. Coders calculated time spent by each child in behavioral categories (positive and negative comments, aggression, nurturance, movement, noise, and gadgetry) and rated children on scales (talkativeness, activity, familiarity, enjoyment, proximity, appropriateness, and gentleness). Sex differences were revealed on most dimensions. Boys were rated as familiar with, enjoying, and playing appropriately with two toys (male-traditional and nonsex-typed) and girls on the female-traditional toy. Girls paid more attention to details of the toys, while there were few differences on aggression and movement. Data suggest that children develop varying patterns of play with the same toy—based on their earlier experiences with play materials. Agents promoting these differences (parents, teachers, and peers) are discussed, as are implications of the findings for children's development of skills and cognitive abilities.
Progesterone was administered to rats perinatally via either maternal Silastic implants (Experiment 1) or daily maternal injections (Experiment 2). Animals were tested at 14 days of age on an active avoidance task (Experiments 1 and 2), and in adulthood on a Lashley III maze task, active and passive avoidance tasks, and open field activity (Experiment 1) and on social and reproductive behavior measures (Experiment 2). Adult males' performance on the Lashley III task was significantly impaired by progesterone treatment in Experiment 1 as were male copulatory and aggressive behaviors in Experiment 2. Perinatal progesterone as administered in these experiments does not results in an animal model for the reported enhancement of human performance consequent to prenatal progesterone treatment. It is, however, consistent with an interpretation of demasculinization of behavior patterns.
This chapter describes an experiment that was conducted to see whether (1) related annual fluctuations in testosterone secretion and the display of sexual behavior occur in male ferrets, and (2) the administration of androgen during perinatal life would, in any way, disrupt the male ferret's normal capacity to display annual reproductive cycles in adulthood. Reproductive function was studied for more than 2 consecutive years in 3 groups of male ferrets. One group received testosterone propionate (TP) both prenatally and on postnatal day 3; a second group received TP on postnatal day 3 only; and a control group received no hormone perinatally. Annual fluctuations in testicular size together with correlated changes in spermatogenesis, the concentration of testosterone in the blood and the incidence of neck grip, mount and pelvic thrusting behaviors occurred in all 3 groups, suggesting that there is no need for the level of testicular secretion of androgen to be particularly low during a critical perinatal period in order for annual reproductive cycles to occur in adulthood.
This paper hypothesizes that sex hormones may have an influence on human brain differentiation and thus play a role in psychosexual differentiation. Such effects, if any, would be clinically relevant to the management of patients with a problem of intersexuality and for the evaluation of pregnancy drugs. A review of studies on patients with endocrine syndromes, including those with an excess or lack of androgen during fetal development strongly suggest that prenatal hormones exert a limited effect on sex-dimorphic behaviors such as physical energy expenditure, childhood rehearsal of parenting, and other related behaviors. The effects of hormone administration during pregnancy are not well known because relevant research studies are rare and often have methodological problems due to the necessary long-term follow-up studies and its attendant logistical problems. Available information therefore is fragmentary. With progestogens, extensive animal research has shown both androgenic and antiandrogenic effects of various progestogens on genital differentiation, gonadotropin regulation, and sex-dimorphic behavior. In humans, administration of certain C-19-derived progestogens has resulted in genital masculinization of a significant minority of female newborns. However, studies have also shown that while these exposed girls exhibited long-term tomboyism, their gender identity was feminine. There was also no evidence that such females, after puberty, developed a homosexual orientation. Boys exposed to medroxyprogesterone acetate in 1 study did not differ significantly from normal controls with respect to a variety of sex-dimorphic behaviors. On the other hand, exogenous estrogens, both steroidal and nonsteroidal, have been shown to exert paradoxical effects on genital morphology and behavior in subhuman animals, i.e., masculinize females and demasculinize males. In humans however, no investigations have yet been reported on behavior effects of prenatal estrogen treatment alone in man, and studies on estrogen-progestogen combination in human subjects have yielded inconclusive results regarding sex-dimorphic behavior.
Reviews the literature on the influence of perinatal gonadal hormones on adult nonsexual behavior patterns in rodents and primates. Perinatal androgens increase the display of adult aggressive behavior in rodents. No research on primates has investigated the effect of perinatal hormones on fighting per se. Instead, high energy expenditure, a trait associated with masculinity in monkeys, has been studied. Female monkeys treated with prenatal androgen exhibit patterns of energy expenditure similar to those of males. Human females exposed to prenatal androgen have been reported by their parents and themselves to show "tomboyish" behavior (i.e. high levels of energy expenditure in play). The effect of perinatal androgen on maternal behavior in rodents is less clear because both male and female rodents will show all aspects of maternal behavior when presented with newborn animals. Human females exposed to prenatal androgen excess have been reported by their parents and themselves to show low levels of maternalism. To explain why genetic females exposed to prenatal androgens were different from controls in regard to energy expenditure and maternalism, researchers have proposed that the behavior changes were a sequel to a masculinizing effect of androgen on the fetal brain. Alternative explanations to postnatal factors are proposed. The influence of perinatal androgen on IQ is also considered. (3 p ref)
Sex differences in many nonreproductive behaviors have been described in rodents. Among the behaviors that are sexually dimorphic in the rat are activity, aggression, pain, and taste sensitivity, food intake and body weight regulation, the learning and retention of certain kinds of mazes, avoidance responses, taste aversion, and performance on certain schedules of reinforcement. Gonadal hormones seem to be responsible, in part, for sex differences in these behaviors, but their contribution varies greatly with the behavior in question. Frequently, these sexually dimorphic behaviors are influenced both by organizational and activational actions of sex hormones. In other instances (e.g., maze learning and the acquisition of shuttle-box avoidance responses) organizational influences predominate. And while there is no sexually dimorphic behavior surveyed that can be shown to be influenced only by activational effects, wheel-running activity is clearly more strongly subject to activational than to organizational effects of the gonadal hormones. In general, only rudimentary information exists regarding the temporal limits of the period in development when organizational influences on nonsexual behaviors occur. The suggestion can be made that organizational influences often occur outside of the critical period for differentiation of the neuroendocrine system regulating cyclic release of gonadotrophins. Even for behaviors where organizational effects usually occur during a roughly delimited period of development, data for other behavioral systems suggest that the time limits during which organizational effects can occur are not rigidly fixed. Very little information exists regarding biochemical or neural mechanisms by which organizational or activational effects on sexually dimorphic nonreproductive behaviors are expressed. It is important to recognize for many of the sexually dimorphic behaviors in the rat that differences between the sexes are neither large nor absolute. This is especially true of several kinds of learning situations where groups of males and females typically differ in average levels of performance. Ostensibly minor variations in test procedure can abolish or accentuate the average difference in performance between the sexes. We are a long way from an adequate understanding of what factors are important, but such information could be quite helpful in estimating whether sex differences in certain laboratory learning tasks have any adaptive significance.Sex differences in nonreproductive behaviors may be influenced by many factors other than hormonal status. This greatly complicates a comparative analysis, but such an analysis will ultimately be necessary. What limited data exist on rodents suggest that: (1) Sexually dimorphic responses in the rat are often not similarly differentiated in the hamster, the gerbil, or the mouse; and (2) major differences exist among rodent species in hormonal effects on such responses.Over the last decade it has become clear that the behavioral effects of deliberate neurological insult are not necessarily the same in male and female rats (or in one case, in rhesus monkeys). Sex differences in the behavioral effects of ventromedial hypothalamic, lateral hypothalamic, septal, and striatal lesions in the rat and of orbital prefrontal cortex lesions in the monkey have been described. While information regarding hormonal modulation of these differences in response to brain damage is very limited, available data suggest both organizational and activational effects of sex hormones may be involved. It is too early to tell where this line of research may ultimately lead, but rather striking sex differences in the incidence of certain neurological disorders in humans suggest that further research may have both practical and theoretical significance.
A wide range of behaviors exhibited by paired, neonatally androgenized (NA) female mice after castration and treatment with testosterone, testosterone and progesterone, or neither steroid was compared with behaviors of similarly treated males. Behaviors shown by NA females and males in aggressive contexts were quite similar. In particular, progesterone inhibited aggressiveness in NA females as it did in males. The data provide further support for the idea that progesterone is antiandrogenic “centrally” to a greater extent than it is antiandrogenic “peripherally.”
As part of a comprehensive interview study, 34 female patients with congenital adrenal hyperplasia (CAH) plus 14 control sisters (ages 11-41 yr.) reported on their psychosexual development and sexual orientation (90 items). Fewer patients than sisters had ever experienced love relationships and sexual activities with male partners (p < 0.05 to 0.001). Twenty percent of the patients and none of the sisters wished for and/or had had homosexual relationships; in the patients > 21 yr 44% expressed this interest (p < 0.07). For most items, patients with the salt-wasting variant of CAH (SW) differed more clearly from the sisters than the simple-virilizing patients (SV). For two scales "indicating" homosexual (HOM) and heterosexual orientation (HET) and for two indices of HOM/HET differences), the patients also revealed relatively stronger homosexual and/or weaker heterosexual interests than the sisters (p < 0.05 to 0.001). Here, too, the SW/sister differences were more clear-cut. These results corroborate earlier reports on both delays in reaching psychosexual milestones and increased rates of bisexual/homosexual fantasies and experiences in CAH women.
Genetic female fetuses were exposed transplacentally to testosterone propionate injected into their mothers either early (Days 40 through 64) or late (Days 115 through 139) in gestation. Early and late androgenized females (EAFs and LAFs, respectively) were raised with normal males and females that served as criteria for evaluating degree of behavioral masculinization induced by the prenatal androgen. EAFs were genitally virilized and LAFs were not. Males and untreated females differed reliably on five behavioral measures: males showed more mother-mounting, more peer-mounting, more rough play with peers, a preference for initiating play with male partners, and less grooming of mothers. Neither type of prenatally androgenized female showed masculinization of all five types of behavior. Compared with females, EAFs showed more mother-mounting, more peer-mounting, less mother-grooming, did not differ from females in rough play, and did not manifest a preference for male partners. LAFs, like females, groomed but did not mount their mothers, and did not show a preference for male partners; but unlike females they showed elevated rough play and mounting with peers. EAFs showed a statistically significant delay in puberty onset (menarche), but LAFs did not. Mothers inspected genitalia of their offspring more often if they were males than if they were females. Mothers of EAFs inspected their offspring's genitalia as often as mothers of males, but mothers of LAFs did not. No aspect of maternal behavior was associated with either the amount or kind of masculine behavior shown toward peers. We interpret the results to mean that genital virilization is independent of, and largely irrelevant to, the expression of those behavioral traits that characterize the juvenile male social role. Moreover, the individual behavior traits that are components of the juvenile male role are independently regulated by the organizing actions of androgen and have separable critical periods. Of the two major traits, mounting peers and rough play with peers, the latter has a greater requirement for androgenic stimulation late in prenatal life.
After a general description of adrenal steroidogenesis, this article reviews the biochemical and genetic abnormalities underlying congenital adrenal hyperplasia and outlines approaches to the diagnosis and treatment of this disorder.
In the first study, the motor activity level and vigor of play of 52 toddlers was assessed as they played with a set of sex-role stereotyped and neutral toys. Boys and girls showed the same level of activity, and both were significantly more active when playing with stereotypically masculine toys. In the second study, 27 toddlers were observed playing with toys defined as potentially eliciting high, medium, or low activity within the masculine, feminine, and neutral categories. Again, boys and girls did not differ in overall activity level. All children preferred toys that allowed moderate to high activity, but given this preference, they selected toys stereotyped for their own gender above those stereotyped for the other gender.
A sexually dimorphic cell group is described in the preoptic area of the human hypothalamus. Morphometric analysis revealed
that the volume of this nucleus is 2.5 +/- 0.6 times (mean +/- standard error of the mean) as large in men as in women, and
contains 2.2 +/- 0.5 times as many cells. Between the ages of 10 and 93 years, the nucleus decreases greatly in volume and
in cell number. Although no function has yet been established for this nucleus, it is located within an area that is essential
for gonadotropin release and sexual behavior in other mammals.
KEY MEASURES OF ANALYTICAL COGNITIVE APPROACH ARE SUBSTANTIALLY RELATED TO SPACE PERCEPTION, AND THEREFORE ARE SEX BIASED. A CONCLUSION OF SEX DIFFERENCES IN ANALYTICAL ABILITY BASED ON THESE DATA APPEARS UNWARRANTED. THE CONSTRUCT OF ANALYTICAL COGNITIVE APPROACH APPEARS QUESTIONABLE. SPACE PERCEPTION APPEARS TO BE A RELEVANT VARIABLE TO CONTROL IN STUDIES OF SEX DIFFERENCES IN GEOMETRIC AND MATHEMATICAL PROBLEM SOLVING. A CAUSAL EXPLANATION OF THE DEVELOPMENT OF SEX DIFFERENCES IN SPATIAL PERCEPTION IS PRESENTED BASED PARTLY ON DIFFERENTIAL PRACTICE. OTHER CAUSAL EXPLANATIONS OF SEX DIFFERENCES IN ANALYTICAL APPROACH ARE DISCUSSED AND AN ATTEMPT IS MADE TO ACCOMMODATE THEM WITHIN THIS FRAMEWORK. (36 REF.)
Sexual differentiation of reproductive and behavior patterns is largely effected by hormones produced by the gonads. In many higher vertebrates, an integral part of this process is the induction of permanent and essentially irreversible sex differences in central nervous function, in response to gonadal hormones secreted early in development.
Among 30 young women with a history of the treated adrenogenital syndrome (CVAH), 11 (37%) rated themselves as bisexual or homosexual. Among a control group consisting of 15 women with the 46,XY androgen-insensitivity syndrome (AIS) plus 12 with the Rokitansky syndrome (MRKS), the corresponding figure was 2 (7%), both bisexual. Chi-square was significant beyond the 0.01 level. In Kinsey's 1953 sample 15% of women experienced homoerotic arousal imagery by age 20, and 10% had had homoerotic partner contact. The most likely hypothesis to explain the CVAH findings is that of a prenatal and/or neonatal masculinizing effect on sexual dimorphism of the brain in interaction with other developmental variables.
Summarizes the literature on perinatal hormone influences in infrahuman mammals, reviews in detail studies on perinatal hormone influences on human behavior, and summarizes methodological procedures that have been used to compensate for problems inherent in research on clinical populations. Several studies provide evidence suggesting that some sex differences in human behavior may be related to prenatal hormone levels. In light of methodological advances and the growing number of studies in this area, it may soon be possible to define human hormone–behavior relations in sufficient detail to allow strong links to research on perinatal hormone effects in other species. Given recent identification of neural sex differences that may underlie behavioral sex differences in infrahuman mammals, such links could lead to greater understanding of the neural basis of sexually dimorphic behaviors in humans. (4 p ref)