1 / 24

Psychology 320: Gender Psychology Lecture 16

Psychology 320: Gender Psychology Lecture 16. Announcement I will hold additional office hours in preparation for the midterm exam: Thursday, October 21: 2 :00-3:00 PM, 3:30-5:00 PM Friday, October 22: 11:30 AM-1:30 PM, 3:30-4:30 PM. Biological Theories of Gender Differences.

colette-austin
Download Presentation

Psychology 320: Gender Psychology Lecture 16

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Psychology 320: Gender PsychologyLecture 16

  2. Announcement I will hold additional office hours in preparation for the midterm exam: Thursday, October 21: 2:00-3:00 PM, 3:30-5:00 PMFriday, October 22: 11:30 AM-1:30 PM, 3:30-4:30 PM

  3. Biological Theories of Gender Differences 1. What biological theories have been proposed to explain gender differences? (continued)

  4. By the end of today’s class, you should be able to: 1. describe the process of prenatal sex differentiation. 2. review evidence that supports genetic contributions to sex differences in psychological characteristics. 3. identify three classes of sex-related hormones. 4. review evidence that supports hormonal contributions to sex differences in psychological characteristics.

  5. What biological theories have been proposed to explain gender differences? (continued) 2. Genetic Theories • Sex determination occurs at conception. • The fertilized egg contains 23 pairs of chromosomes—the pair that determines the sex of the individual is pair number 23.

  6. Those individuals who inherit two X chromosomes develop into females; those individuals who inherit an X chromosome and a Y chromosome develop into males. • Only the sperm cell is capable of contributing a Y chromosome. Thus, the sperm cell determines the sex of the offspring.

  7. The Y chromosome carries a gene (SRY gene) that acts as a “switch” for maleness, initiating processes that result in the development of a male offspring. • During the 7th week of gestation, the SRY gene directs the production of testis-determining factor (TDF). TDF triggers the development of testes, rather than ovaries, from embryonic gonad tissue. • Androgenic hormones from the testes (i.e., müllerian inhibiting factor, testosterone) enable further develop- ment of the male internal reproductive system.

  8. NO ANDROGENIC HORMONES ANDROGENIC HORMONES

  9. Research suggests that, in addition to sex differentiation, genes influence gender development.

  10. Example 1: Twin Studies Lippa and Hershberger (1999) • Analyzed data collected from 839 same-sex pairs of twins. • Among the measures that participants completed were: the Adjective Checklist, occupational interests, and frequency of everyday activities.

  11. Heritability statistics obtained: Masculine instrumentality = .36 Feminine expressiveness = .38 GD = .53 • These findings replicate the results of several other studies.

  12. Example 2: Genetic Atypicalities Klinefelter Syndrome • Results from an extra X chromosome in males (XXY). • Those with Klinefelter syndrome develop testes, a penis, and a scrotum, although these structures may be relatively small and associated with sterility. • Incidence: 1/1000 – 3/1000 live births.

  13. Physical symptoms include: • small firm testes small penis underdeveloped muscles rounded body type (i.e., wide hips) abnormal body proportions tall build gynecomastiareduced facial/body hairlanguage learning impairmentdecreased libidoinfertilityepilepsy • Psychological symptoms include: “incomplete masculinization.”

  14. 3. Hormonal Theories • Circulating hormones influence the differentiation of the sexual reproductive system, affect the development of the central nervous system, and influence both psychological processes and behaviour.

  15. There are three primary classes of sex-related hormones: Estrogens (e.g., estradiol, estrone; in relatively high concentrations in females). Progestins (e.g., progesterone). Androgens (e.g., testosterone, androstenedione; in relatively high concentrations in males).

  16. Estrogens and androgens are particularly important in the sex differentiation of the reproductive system of the fetus, the maturation of the reproductive system at puberty, and the development of secondary sex characteristics at puberty. • Research suggests that, in addition to sex differentiation, hormones influence gender development.

  17. Example 1: Non-Human Animal Experiments vom Saal, Grant, McMullen, and Laves (1983) • Contrasted the behaviour of male mice exposed to high prenatal testosterone levels and male mice exposed to low prenatal testosterone levels. • Target embryos were “placed” between two male siblings or two female siblings, resulting in differential exposure to testosterone. • Males exposed to higher testosterone levels displayed more aggressive behaviour postnatally.

  18. Biological Explanations of Gender Differences: 1. What biological theories have been proposed to explain gender differences? (continued)

More Related