Sex differences Messinger Gender film clips Bonobo

Overview

Biology's role n n n “Experiments with nonhuman primates show that administering testosterone to female fetuses late in gestation yields more typically masculine behavior. ” Placement of rat fetuses in utero influences sex-typed behavior Many sex differences are continuous, not categorical n E. g. estrogen and testosterone

Sex Differences in Early Infancy n “girls show stronger visual preferences for a doll (i. e. , an object with human attributes) than for a toy truck • (Alexander, Wilcox, & Woods, 2009)… n boys shortly after birth show stronger visual preferences for a mechanical mobile than for a face • (Connellan et al. , 2000)” Alexander, G. M. , & Wilcox, T. (2012). Sex Differences in Early Infancy. Child Development Perspectives, 6(4), 400 -406. doi: 10. 1111/j. 1750 -8606. 2012. 00247. x

Feedback n Between physical and social features

z Simpson, Nicolini, Shetler, Suomi, Ferrari, & Paukner (2016) Experience-independent sex differences in newborn macaques: Females are more social than males

z Background § Gender differences may be attributed to different evolutionary pressures § Females – primary caretakers § increased social interests & skills interpreting expressions increased offspring survival § However, male and female human infants are treated differently from birth § § Parents handle male infants more “rough” & spend more time in synchronous interactions with mothers Offer female infants more verbal stimulation & get more parentchild interaction overall

z Current Study § Nonhuman Primate Studies § More control over experiences and environments § Macaques have similar patterns in sex-related differences § Goal: assess sex differences in macaque infants raised in homogenous controlled environments (nursery)

z _ § Methods 48 healthy, full term macaques (21 Female) § Separated from mothers at birth § Tested before exposed to social groups § Eye tracking test at 2 -3 weeks old § Human interaction task at 4 -5 weeks old

z _ Eye Tracking Task § Across both measures there are main effects of sex § Females look at faces longer regardless of expression than their male counterparts § Females also specifically spend more time looking to the eyes and mouths of the face

z _ Human Interaction Task § Sex differences only in Affiliative Social Behaviors § Females significantly outperformed the males

z Take-homes § First study to provide evidence for “experience-independent” sex differences in social behaviors soon after birth in any primate (humans included) § Limitations: § § Possible subtle differences in the way caregivers treated infants § § No control stimuli Disentangle social skills & social motivation Questions? § How do you feel about the procedures in both eye tracking task and human interaction task? § Do you expect similar results if we could do this with human infants? § Pre-natal environment differences? § Did you buy it?

Male newborns n ‘Less responsive to social stimuli n n n less able to maintain eye contact Greater difficulties in maintaining affective regulation Smile less and display more irritability, crying, facial grimacing, and lability of emotional states n n more rapid buildup of arousal engage in less self-comforting’ • Weinberg et al. , p. 175

Face-to-face Joy Interest Anger Look @ Mom Look @ Object Neutral/Positive Vocalizations Fussy Vocalizations Boys. 26. 55. 07. 42. 35. 13 Girls. 16. 68. 03. 35. 45. 06 . 09 . 04 (Weinberg et al. )

Mothers more likely to talk to n engage in face-to-face interaction n hold and touch n their male infants n n possibly in an attempt to soothe them

Differential social expectations Pervasive: TV, media n Experimentally demonstrated n Define normative expectations of everyday behavior and n Define boundaries of acceptable behavior n At the most intimate and the most mundane levels n

Maccoby n "By and large, the daily routines of family life do not have much impact on the strong tendency of children to separate into same-sex groups, and probably not on the distinctive activities enacted by male and female groups, " Maccoby said.

Gender segregation n Research on gender typing in individuals is inconclusive Clustering of gender-typed characteristics weak n Relations to family characteristics weak n n Same-sex groupings predominate From 3 – 12, n Cross-cultural phenomenon n

Constructivist argument Innate gender-specific proclivities n Lead to same sex segregation n Which creates gender-specific socialization n Children create themselves playing with each other n n IS THIS POSSIBLE?

Same-sex groupings n Boys n Larger groups n More conflict/competition n Cohesiveness n More autonomous from adults n Girls n n n Smaller, more dyadic Less conflict, more responsive Less goal-oriented, more intimate n. Differential exposure to these groups influences individual behavior

Sex differences n With increasing age, boys and girls in preschool interact with members of the same sex • n (e. g. , Fabes, Shepard, Guthrie, & Martin, 1997; Maccoby & Jacklin, 1987; Martin & Fabes, 2001). By 4 -5 years of age, both boys and girls are observed interacting with same sex peers at three to four times the frequency that they interact with other sex peers.

Day-to-day variability Girls Same-sex preference Other-sex preference Boys

Dynamic system approach to gender research n Long term changes and short term interactions. Lynn Martin, C. , Fabes, R. A. , Hanish, L. D. , & Hollenstein, T. (2005). Social dynamics in the preschool. Developmental Review, 25(3– 4), 299 -327. doi: http: //dx. doi. org/10. 1016/j. dr. 20 05. 10. 001

“Fig. 4 A represents the state space pattern that might be seen for a socially competent boy who is solely attracted to other socially competent children. “ “Fig. 4 B illustrates a pattern based on sex similarity. In this case, the events represented on this boy’s state space illustrate that he is seen interacting only with boys and it does not matter what type of social behavior they tend to display. “ “Fig. 4 C depicts the landscape for a socially competent boy whose state space is shaped by both similarity on social behavior and on sex. The events cluster in the region of socially competent boys. If this pattern occurred, it would suggest that behavioral similarity matters but only in consideration for same-sex peers. ”

Sex-Segregated Interactions

New approaches

Child Mobility. ppt

Digit Ratio (2 D: 4 D) and attachment styles in middle childhood: Indirect evidence for an organizational effect of sex hormones Marco Del Giudice & Romina Angeleri (2015) Will M.

Life history theory How to make trade-offs between growth, maintenance, and reproduction over the life course given a limited amount of energy. “Fast” strategy: mature early, reproduce early, have many offspring, invest less in them, die earlier E. g. , Salmon “Slow” strategy: mature late, reproduce later, have fewer offspring, invest more in them, die later E. g. , Humans Will M.

Does 2 D: 4 D digit ratio predict attachment in middle childhood? Second digit typically shorter, but difference between lengths of the two digits greater in males than females. n Rough-and-ready measure of early exposure to androgen and estrogen. n Should predict differences in insecure attachment in both sexes n Will M.

Mean digit ratio higher in females § § § Females score lower in avoidance, higher in ambivalence No sex differences in secure attachment More feminine ratios associated with less avoidance, more ambivalence, not felt security Will M.

Aggression type and gender n Boys more physically victimized by their friends. n n Friend physical victimization was particularly related to boys adjustment difficulties Girls more relationally victimized. n n Friend relational victimization was particularly related to girls’ adjustment difficulties. Crick & Nelson, 2002.

Prediction

Cross-sex friendships Pre-school n Elementary school n Middle school n High school / Adolescence … n

Change n 12 th grade Boys 5 hrs a week w girls. n Girls 10 hrs a week w boys. n n Larger network of other-sex friends increases odds of romantic relationship

Extreme male brain theory of autism Baron-Cohen

Empathizing (theory of mind) n “Empathizing is the capacity to predict and to respond to the behavior of agents (usually people) by inferring their mental states and responding to these with an appropriate emotion. ”

Systemizing n “Systemizing is the capacity to predict and to respond to the behavior of nonagentive deterministic systems by analyzing inputoperation-output relations and inferring the rules that govern such systems. ”

Females and males n n n “At population level, females are stronger empathizers and males stronger systemizers. “Eextreme male brain’’ theory: autism represents an extreme of the male pattern (impaired empathizing and enhanced systemizing). Specific aspects of autistic neuroanatomy may also be extremes of typical male neuroanatomy. ”

You can be high in both… or low in both n Higher on graph – more empathizing n n Lower – less empathizing More to right – higher systemizing n More left – less systemizing

AS/HFA>Male>Female

Sex differences attenuated in ASD…. Baron-Cohen, S. , Cassidy, S. , Auyeung, B. , Allison, C. , Achoukhi, M. , Robertson, S. , Pohl, A. , & Lai, M. -C. (2014). Attenuation of Typical Sex Differences in 800 Adults with Autism vs. 3, 900 Controls. PLo. S ONE, 9(7), e 102251. doi: 10. 1371/journal. pone. 01 02251

What about the development of ASD? Messinger, D. S. , Young, G. S. , Webb, S. J. , Ozonoff, S. , Bryson, S. E. , Carter, A. , Carver, L. , Charman, T. , Chawarska, K. , Curtin, S. , Dobkins, K. , Hertz-Picciotto, I. , Hutman, T. , Iverson, J. M. , Landa, R. , Nelson, C. A. , Stone, W. L. , Tager-Flusberg, H. , & Zwaigenbaum, L. (2015). Early sex differences are not autism-specific: A Baby Siblings Research Consortium (BSRC) study. Mol Autism, 6, 32. doi: 10. 1186/s 13229 -015 -0027 -y

Proportion ASD Relative risk of ASD = 3. 18

Sex by domain not affected by group Repetitive Behaviors Social Affect

Sex by subtest not affected by group

Conclusion n n Sex differences in ASD prevalence No sex differences in overall symptoms or cognition • Boys (higher RRB) and girls (higher language) with ASD differ in specific performance areas • These sex differences exist in ASD, non-ASD, low-risk n n Results are consistent with recent reports Sex differences that appear in children with ASD may not be ASD-specific

Effect of female sibling n Palmer, N. , Beam, A. , Agniel, D. , Eran, A. , Manrai, A. , Spettell, C. , . . . Kohane, I. (2017). Association of Sex With Recurrence of Autism Spectrum Disorder Among Siblings. JAMA Pediatr. doi: 10. 1001/jamapediatrics. 2017. 2832

Homosexuality as a Discrete Class n Previous research on the latent structure of sexual orientation has returned conflicting results, with some studies finding a dimensional structure (i. e. , ranging quantitatively along a spectrum) and others a taxonic structure (i. e. , categories of individuals with distinct orientations). n n Low-base-rate same-sex-oriented taxa for men (base rate = 3. 0%) and women (base rate = 2. 7%). n n The current study used a sample (N = 33, 525) from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). A series of taxometric analyses were conducted using three indicators of sexual orientation: identity, behavior, and attraction. Generally, taxon membership conferred an increased risk for psychiatric and substance-use disorders. Although taxa were present for men and women, women demonstrated greater sexual fluidity, such that any level of same-sex sexuality conferred taxon membership for men but not for women. n Norris, A. L. , Marcus, D. K. , & Green, B. A. (2015). Psychological Science. doi: 10. 1177/0956797615598617

Female Bisexuality From Adolescence to Adulthood: Results From a 10 -Year Longitudinal Study. Lisa Diamond n 3 conceptualizations of bisexuality 1. “Transitional phase” 2. Third type of sexual orientation 3. Heightened capacity for fluidity n Present study n n 79 non-heterosexual women 10 years, 5 assessment points. At each: • Label self sexual identity • Lesbian, bisexual, “unlabeled” • % daily attractions that are same-sex • #of sexual contacts with men & women (since last assessment) Nayfeld

Identity n Changing identity • 73% of T 1 bisexuals • 83% of T 1 “unlabeled” • 48% of T 1 lesbians n Bisexual and unlabeled women more likely to change identity labels, χ2(2, N = 79) = 8. 3, p <. 02. More likely to switch between bisexual and unlabeled IDs than to settle on lesbian or heterosexual labels. • 2/3 of ID changes: adopting bisexual or unlabeled identity. n % identifying as bisexual or “unlabeled” • T 1 T 2 T 3 T 4 T 5 57% 47% 51% 57% 58% Nayfeld

Sexual Attractions • Same-sex attractions declined significantly among lesbians only • Women who gave up bisexual/lesbian IDs still reported bisexual patterns of attraction in T 5 Nayfeld

Sexual Behavior Consistent decline in same sex behavior among all women NOT matched by a parallel decline in same -sex attractions By 2005, most women involved in long term monogamous relationships. 70% of T 5 lesbians, 89% of bisexuals, 85% of unlabeled women, 67% of heterosexuals By 2005, 60% of T 1 lesbians had sexual contact with a man, and 30% had been romantically involved with a man Resolved by change in identity to bisexual/unidentified Nayfeld

Discussion n • • Bisexuality as stable pattern of attraction to both sexes, with balance varying based on personal and situational factors. Identity change more common than identity stability ID change reflects shifting experiences Adopt labels consistent with relationship status Seek to maximize fit with own prevailing pattern of attraction/behavior Nayfeld