2 How do we (as scientists) find out about sex? Sex Is NaturalWe are all motivated to have sex.Without that motivation, none of us would be here.How do we (as scientists) find out about sex?We ask!!!!
3 Kinsey’s StudiesConfidential interviews with 18,000 people (in early 1950’s).Most men and half of all women have premarital sex.Almost all men and women masturbate.Women who had orgasms while masturbating were more likely to report having orgasms after marriage.Good Start- but major problems with his study- sampling, questions etc….
4 The Physiology of SexIn the 1960’s William Masters and Virginia Johnson set out to explore the physiology of sex.382 females and 312 males.Only people who were willing to have sex and display orgasm in a lab environment.Filmed more than 10,000 sex cycles.
5 The Sexual Response Cycle (Four Stages) Results of M & J StudyThe Sexual Response Cycle (Four Stages)Excitement Phase: genitals become engorged in blood (men and women) and women will lubricate.Plateau Phase: excitement peaks, breathing, pulse increases, tip of penis may exhibit seminal fluid, clitoris retracts- orgasm feels imminent.
6 Results of M & J Study (Continued) Orgasm: muscle contractions all over the body, women’s contractions actually help propel sperm and position uterus to increase chances of conception. Man and woman only aware of rhythmic genital contractions.Resolution Phase: everything slows down and men enter a refractory period (which can last from minutes to over a day) where he is incapable of another orgasm.
7 The Psychology of SexOnly some people are externals when it comes to hunger- but we are all externals when it comes to sex.Heiman 4 tape study.People can find sexually explicit images either pleasing or disturbing- but they are none the less biologically arousing.
8 Can External Sexual Stimuli have adverse effects? Movies of women being coerced or forced into sex tend to increase the viewer’s acceptance of the false idea that women can enjoy it.Viewing X-Rated films can diminish people’s satisfaction with their own partners. Expectations change.After viewing attractive women or men on TV- people judge their own partners as less attractive.
9 Imagined StimuliImages inside our heads can also effect our sexual motivation.Both dreams and daydreams can lead to orgasm.But fantasies to not correspond to reality- just because a women fantasizes about a man “taking her” does not mean she will want it in reality!!!!
10 Adolescent Sexuality Culture About ½ of all high school kids in US report having sex- rates are higher in Western Europe but lower in Arab or Asian countries.Also change over time in the same culture: in % of women reported having sex by 18. Now that number is around half.
11 Only about 1/3 of sexually active male teenagers use condoms- WHY? IgnoranceGuilt around sexNo CommunicationAlcohol UseMass Media norms of unprotected promiscuity
12 We have discussed the energizing of sexual motivation but have yet to discuss its direction: Sexual OrientationAn enduring sexual attraction toward members of either one's own gender or the other gender.Percentage gay, how it feels, cities, brothers.
13 How is Sexual Orientation Determined There has been NO evidence that sexuality is socially determined.Kids raised by gay parents are no more likely to be gay that if they were raised by hetero parents.Thus, it is likely that sexuality is biologically determined.
14 The BrainSimon LeVay discovered that there is a cluster of cells in the hypothalamus that is larger in heterosexual men than in heterosexual women or homosexual men.However, the cluster could be socially developed or some other biological factor.
15 Genetics What does this mean? If one identical twin is homosexual, the other twin has about a 50% chance of being gay (about 20% for fraternal twins).What does this mean?
16 Prenatal EnvironmentCurrent research seems to point to the hormonal levels in the prenatal environment.We have been able to create lesbian sheep!!!What are the ethical issues here?