1. DO NOW: HOW MIGHT EVOLUTIONARY PSYCHOLOGIST EXPLAIN THE IMPORTANCE OF A SEX DRIVE/MOTIVATION? Motivation Sex 1

2. AIM How is the behavior of sex motivated? 2

3. Importance of Sex Continuation of the species 3

4. Behavioral Patterns Alfred Kinsey Kinsey Institute Problem with Sex Polls not Poles 4

5. Physiology of Sex Stages of sexual response cycle Initial excitement Plateau phase Orgasm …oops baby? Resolution 5

6. Physiological Effects on Sexual Motivation Sex hormones (testosterone and estrogen) Results: Removal of ovaries in women did led to lower sex drive yet removing testes in men sex drive gone. Inference? Testosterone has the greatest impact on sex motivation Puberty 6

7. Psychology of Sex External motivation Cultural Influences 7

8. Homosexuality: Nature or Nurture What kind of evidence do we need to support nature? Nurture? How could we test nurture? Ethical implications 1990’s results: genetic marker on X chromosome in men found in gay men but not straight men. Valid? Twin studies 8