1 Psychology 320: Psychology of Gender and Sex Differences October 15 Lecture 11

2 Office Hour Invitations October 15, 2:30-4:30PM, Kenny

3 Opportunities! 1. “Alternative Guy’s Nights offer an environment free of judgment to talk about everyday (or extraordinary) experiences that shape our lives as men …. ask questions, share thoughts, and explore … perspectives.” When: Regularly scheduled events. Next event on Thursday, October 15, 6:00-7:30PM (Drinking Culture/s). Where: ANSO 141. Information: com/events/alternative-guys-nights/

4 2.STUDENT DIRECTED SEMINAR: ASTU 400Y Interdisciplinary Approaches to Religion: Psychological, Social and Cultural Effects Term 2, Tuesdays, 5:00-8:00PM, IBLC 156 Student Coordinator: Anica Villamayor “This course will examine the impact of religion on individuals and societies. Students will critically evaluate topics related to the psychological, social and cultural effects of religion, using an inter- disciplinary approach. Course topics will include ethics, crime, identity, development, personality, sexuality, healthcare, and more. Students will participate in thought-provoking discussion in a collaborative learning environment. Assessments will include a presentation, a paper, and peer evaluations. Interested students should send a statement of interest to the course facilitator that outlines relevant academic and/or non-academic experiences, the contributions that they believe they will make to the course, and their learning goals for the course See

A little R&R …. (Review and Reflect) 5

6 Let’s Revisit … October 13 lecture slides, slides 23-29: 3. Stereotype Threat

7 Female Identity Salient Asian Identity Salient No Identity Salient Proportion of Correct Answers on Math Test (Shih, Pittinsky, & Ambady, 1999) Significant differences between identity and no identity conditions, p<.05.

8 Biological Theories of Sex Differences 1. What biological theories have been proposed to explain sex differences?

9 2. define the terms reproductive capacity and minimal parental investment. 1. discuss the application of evolutionary theory to the study of sex differences. By the end of today’s class, you should be able to:

10 4. describe the process of prenatal sex differentiation. 3. relate sex differences in reproductive capacity and minimal parental investment to sex differences in mate preferences.

11 What biological theories have been proposed to explain sex differences? Biological theories of sex differences can be classified into four groups: 1. Evolutionary Theories  Evolutionary psychologists have adapted Darwin’s theory of evolution to the study of sex differences.

12  Darwin argued that characteristics that enhance the survival and reproductive ability of organisms increase in frequency across successive generations, resulting in the “evolution” of the species.

13  Given sex differences in reproductive capacity and minimal parental investment, evolutionary psychologists maintain that males and females have developed distinct characteristics to maximize their reproductive potential.

Psychology Reproductive capacity: Males > Females  Males: Can bear an almost unlimited number of offspring across the lifespan (maximum recorded to date: 900).  Females: Can bear 8 – 12 offspring across the lifespan. 14

Psychology Minimal parental investment: Females > Males  Females: Carry and nourish fetus for 9 months; nurse child after birth; during lactation, ovulation is suppressed.  Males: Engage in copulation. 15

16  Example: Sex differences in mate preferences Hypothesis: Given sex differences in reproductive capacity and minimal parental investment, males have evolved to value appearance in a mate more than females, and females have evolved to value resource potential in a mate more than males.

17 Evidence: Had participants rate several characteristics for their desirability in a potential mate: 0=irrelevant, 3= indispensable. Buss and Angleitner (1989; see also Buss et al., 2005)

18 Pleasing disposition Sociability Neatness Mean Rating Male Female Dependability Good looks Good financial prospects Ambition and industriousness Good health

19 2. Genetic Theories  Sex determination occurs at conception.  The fertilized egg contains 23 pairs of chromosomes; the pair that determines sex is number 23.

20  Only the sperm cell is capable of contributing a Y chromosome. Thus, the sperm cell determines the sex of the offspring.  Female: Pair 23 contains two X chromosomes. Male: Pair 23 contains an X and a Y chromosome.

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23  During the 7 th week of gestation, the SRY gene directs the production of testis-determining factor (TDF), which triggers the development of testes.  The Y chromosome carries the SRY gene that acts as a “switch” for maleness, producing a male offspring.

24  Androgenic hormones from the testes (i.e., müllerian inhibiting factor, testosterone) result in further development of the male internal reproductive system.

ANDROGENIC HORMONES NO ANDROGENIC HORMONES 25

26 2. define the terms reproductive capacity and minimal parental investment. 1. discuss the application of evolutionary theory to the study of sex differences. By the end of today’s class, you should be able to:

27 4. describe the process of prenatal sex differentiation. 3. relate sex differences in reproductive capacity and minimal parental investment to sex differences in mate preferences.