Lecture Notes for Biology 203, Human Sexuality and Reproduction

  1. Sexual Attitudes and Behaviors
    1. Reliability of research into sexual attitudes and behaviors limited by design of study and method of data collection
      1. Collection of information by survey less dependable than by interviews
      2. Selection of sample population may affect results: college students, magazine subscribers, self-selected groups not representative of general population, often too small
      3. Quality of information limited by person's memory, may not be truthful or complete, may seek to please interviewer, may be anecdotal in some studies
    2. Kinsey (men, 1948; women, 1953)
      1. First collection of information about sexual attitudes and behaviors
      2. Interviews, but not random or representative sample of population
      3. Results unexpected, but comforting to many who had thought they were unique in feeling, behaviors
    3. NHSL Survey (1992, National Health and Social Life Survey)--see paper or online handout)
      1. Results published for lay people in book, Sex in America
      2. Used more sophisticated, modern sociological research methods
      3. Carefully chose sample population to be random, representative (see table)
      4. Interviewed only randomly chosen person in household at randomly chosen address, from randomly chosen neighborhood, town or rural area, and geographic area
      5. Of 4369 randomly chosen individuals, managed to get interviews with 3430 (good percentage)
      6. Survey limited to those of ages 18 to 59, those who spoke English, and those who had homes
      7. Sample population matched to demographics of US population in gender, age, education, marital status, and race/ethnicity distributions
      8. Key findings
        1. Who are our sexual partners?
          1. Partners tend to be similar to ourselves
          2. Similar in race, educational level, religion, age, etc.
        2. Where do we find our sexual partners?
          1. Meet through people we know (mutual friends, family)
          2. 30% self-introduced, 10% bars, ads, etc.
          3. Meet at work, in gyms, at parties, in class, at church, etc.
        3. The older people were, the more likely it was that their first sexual partnership was marriage.
          1. For men and women born between 1963 and 1974, 34% and 35% respectively
          2. For men and women born between 1933 and 1942, 84% and 94% respectively
        4. How many sexual partners had people had in the last 12 months?
          1. 94% of married people had had only one partener
          2. 75-80% of those cohabitting had only one partner
          3. Of those not married and not cohabiting, 25% had had 0 partners, 38% had had one, 28% had had 2 to 4, and only 9% had had more than 5
          4. Singles not as sexually active with multiple partners as had been thought
        5. How often did people have sex?
          1. Overall, all ages 18-59, average of twice a week
          2. About 1/3 greater than or equal to twice a week, about 1/3 few times a month, about 1/3 few times a year
          3. Nether age, married/cohabiting, or length or relationship affected frequency of sex
          4. Being part of a couple (any kind) was most important factor in being sexually satisfied
          5. Nonmarried, noncohabitting people were the group least sexually satified
        6. What sexual practices do people find most appealing? (first and second choices)
          1. Women (both 18-44 and 45-59): vaginal intercourse, watching partner undress
          2. Men (both 18-44 and 45-59): vaginal intercourse, watching partner undress
  2. Sexual Orientation
    1. Sexual behavior is not easily measured
    2. People change their sexual behavior during their lives
    3. No one set of behaviors is sufficient to identify a person's sexual orientation
    4. Sexual orientation can be described in three ways
      1. Sexual desire: to whom is the person attracted
      2. Sexual behavior: with whom the person chooses to have sex
      3. Self-identification: self-labeling as heterosexual, homosexual, bisexual, etc.
    5. NHSL Survey
      1. People who identify themselves as homosexual in any one of the three ways above
        1. Women: 8.6%
        2. Men: 10.1%
      2. Approximate percentages of men and women identifying themselves in the three areas
        Characteristic Sexual desire Sexual behavior Self-identification
        Men 5 6 2.8
        Women 4 5.5 1.4
    6. Kinsey scale (0, exclusively heterosexual, to 6, exclusively homosexual)
    7. Storms scale (two-dimensional, includes asexual, bisexual)
    8. Correction of common homosexual stereotypes
      1. There are no behaviors and mannerisms that identify homosexuals as such.
      2. Homosexual men do not necessarily exhibit effeminate behaviors/mannerisms.
      3. Homosexual couples do not necessarily play the same roles as heterosexual couples do within their partnership.
      4. Homosexuals are far less likely to sexually molest children than heterosexuals.
    9. Types of couples (homosexual, but find same types among heterosexuals)
      1. Couples with long-term relationships
        1. Men, 28%; women, 45%
        2. Some closed relationships (only with one partner, more stable)
        3. Some open relationships (more than one partner, less stable)
      2. Functional individuals (single, sexually active): men, 27%; women, 15%
      3. Short-term relationships, often one partner at a time
      4. Asexual individuals
    10. Frequency of sex: men, 2-3 times a week; women, 1-2 times a week
    11. Women who are homosexual tend to have fewer sexual partners, to have longer lasting, more stable relationships, and are less likely to be very visible to their community
    12. Men who are homosexual tend to have many more partners, to be more promiscuous, to have shorter relationship, and are more likely to be very visible to their community
    13. Causes (many hypotheses, none confirmed, some now thought to be unlikely, most based on studies of unhappy or poorly adjusted homosexuals)
      1. Exposure to certain types of parenting
      2. Childhood experiences and behaviors
      3. Age at puberty
      4. Hormonal variations
      5. Genetic and/or physiological differences
        1. Differences in brain anatomy/function?
        2. Multiple genes involved in predisposition to homosexuality, but would require another factor or factors, as yet unknown, to trigger expression of sexual orientation
  3. Sexual Coercion (Rape and Sexual Assault)--see Sexual Assault Questionnaire (annotated) and handouts