AP Psychology
Unit 10: Motivation
Sexual Motivation

Notes Outline

  • Human Sexual Response
  • Evolution & Parental investment
  • Gender differences in sexual activity
  • Gender differences in mate selection
  • Pornography
  • Sexual Orientation

First Things First...

Let's make sure we are all talking about the same things....

Human Sexual Response

Research of William Masters and Virginia Johnson in 1960’s -- > Actually researched sex in a clinical setting. Determined there were four stages

  1. Excitement Phase – Physical arousal, muscle tension, heart rate, and blood pressure quickly increases.

  • VASOCONGESTION – engorgement of blood vessels -- > Erection in men, similar engorgement of vulva, clitoris, and vaginal entrance in women

2.  Plateau Phase – Physiological arousal continues to build slowly, but may increase or decrease

3.  Orgasm Phase – Orgasm is a series of muscular contractions in the pelvic area accompanied with increased heart rate, respiration rate, and blood pressure, a release of endorphins that create a euphoric feeling, and ejaculation of seminal fluid by men

  • Orgasm Gap – Women can immediately orgasm again and experience multiple orgasms, HOWEVER far fewer women report orgasming in every sexual experience than men. Relationship quality seems to be a much larger factor for women orgasming than men.

4. Resolution Phase – Physical arousal subsides -- > REFRACTORY PERIOD for men when they cannot become aroused or ejaculate again.

Evolution & Parental Investment

Sex is fundamentally for the furthering of the species, but the question of why we have sex with the people we do led Trivers to his PARENTAL INVESTMENT THEORY

PARENTAL INVESTMENT THEORY – discusses which sex has to invest in terms of time, energy, survival risk, and forgone opportunities to produce and nurture offspring

  • Members who make smaller investment (usually males) will pursue mating opportunities vigorously and compete for ‘best’ mates. Males are required only the time needed to mate.
  • Members who make a larger investment (usually females) tend to be more discriminating and conservative about mating behavior. Females are required not only the time of mating, but nine months of gestation, and up to several years of nurturing the child

Gender Differences in Sexual Activity

Things Research Has Shown:

  • Males generally show a greater interest in sex than females do (Peplau, 2003)
  • Men think about sex more than women (Laumann et al., 1994)
  • Men initiate sex more than women (Morokoff et all., 1997)
  • Males have more frequent and varied sexual fantasies (Okami & Shackford, 2001),
  • Men’s subjective perception of their sex drive tend to be higher than females’ (Ostovich & Sabini, 2004)
  • Men tend to overestimate women’s sexual interest in them (women do not share this bias)
  • By age 55-64 62% of men but only 38% of women report that they are still very interested in sex (Lindau & Gavrilova, 2010)

Gender differences in mate selection

  • Evolutionary theory says males should seek a mate who is younger, attractive, and will be faithful
  • Evolutionary theory says females should seek a mate who could provide material resources and willingness to invest resources in family
  • CRITICISIM of EVOLUTIONARY THEORY– Is this the case simply because we are taught by all of our cultures that it should be so? Are female’s focus on males economic impact simply a result of female’s historically limited access to economic resources? Are female’s sexual patterns an extension of cultural processes that seek to limit and marginalize female sexuality?


"...Edward Wilson says we need to understand that human sexuality is first a bonding device and only secondarily procreation. I think that's true. This matters because our evolved sexuality is in direct conflict with many aspects of the modern world. The contradictions between what we're told we should feel and what we actually do feel generates a huge amount of unnecessary suffering. My hope is that a more accurate, updated understanding of human sexuality will lead us to have greater tolerance for ourselves, for each other, greater respect for unconventional relationship configurations like same-sex marriage or polyamorous unions, and that we'll finally put to rest the idea that men have some innate, instinctive right to monitor and control women's sexual behavior. (Applause) Thank you. And we'll see that it's not only gay people that have to come out of the closet. We all have closets we have to come out of. Right? And when we do come out of those closets, we'll recognize that our fight is not with each other, our fight is with an outdated, Victorian sense of human sexuality that conflates desire with property rights, generates shame and confusion in place of understanding and empathy. It's time we moved beyond Mars and Venus, because the truth is that men are from Africa and women are from Africa."


Pornography has never been more prevalent, especially within the United States

  •   No evidence has been found to link sex crimes with pornography
  •   HOWEVER, there is significant evidence to suggest that certain types of pornography, AGGRESSIVE PORNOGRAPHY, that depict violence, rape, or women giving into degrading acts after initial resistance DOES have a correlation to violence or sexually aggressive acts in men already at risk for these behaviors
  • Estimates suggest that upwards of 25% of women will be a victim of rape or attempted rape – the majority of rapists are NOT strangers
  • ALSO - The majority of pornography portrays a male/female sexual encounter where there is limited foreplay and the culmination is male ejaculation, which signals the end of the encounter. This can be harmful to the development of healthy sexuality in both genders, or at least lead to misconceptions of sex.

Sexual Orientation

Sexual Orientation refers to a person’s preference for emotional and sexual relationships with individuals of the same sex, the other sex, or either sex. Heterosexuals=opposite sex; Homosexuals=same sex; Bisexuals=either sex

NOT A ONE OR THE OTHER THING -- > sexuality is a continuum with hetero- and homosexuality on either end

  • Female’s sexuality appears to be more fluid than males
  • So why are some people homosexual and some heterosexual (and many more someplace in between)?
  • Freud said it was a weak father and overprotective mother – RESEARCH DOES NOT SUPPORT THIS
  • Behaviorists said this was a result of classically conditioned stimuli paired with sexual stimulation in childhood – RESEARCH DOES NOT SUPPORT THIS
  • Research DOES support that sexual orientation is something that starts in childhood, if not before birth. Gender nonconformity in childhood is often an indicator of sexual orientation.
  • Research DOES support the idea of a genetic component, or at least hereditary disposition
  • Research DOES support the idea that the presence of above average androgens or estrogens at critical stages in utero permanently develop the brain in a certain manner that would predispose a person to homo- or heterosexuality