Human Sexuality Sexuality in Biological Perspective

Puberty Rapid physical maturation Hormonal/bodily changes Role of genes and environments

Pubertal Growth Spurt Fig. 3.3

Changing Trends in Puberty Onset of puberty beginning earlier United States: menarche at 15 in 1840s, now 12½ Caucasian girls at average age of 10 African American girls at average age 8 to 9 **How does this impact psychological and sexual development?

Sexual Development Puberty in girls: menarche (age 12/13) –Sexual maturation continues until age 16 (approximately) Puberty in boys: spermarche (age 13/14) –Sexual maturation continues until age 18 (approximately)

Body Image in Puberty –Throughout puberty… Girls’ dissatisfaction increases — body fat increases Boys’ satisfaction increases — muscle mass increases Which factors influence body image?

Early vs. Late Maturing Boys Early maturing boys perceive themselves more positively and have more successful peer relationships than late maturing boys

Early Maturing Girls Early maturing girls: –At risk for smoking, drinking, depression, eating disorders –At risk for unwanted pregnancies

Early Maturing Girls –Tend to have older friends –Earlier dating/sex –Lower educational/occupational attainment –Higher incidence of mental disorders

Early Maturing Boys and Girls Associated with: –greater use of alcohol and drugs –high risk sexual behavior –getting into trouble with the law

Maturation Rates Girls who mature early and boys who mature late: –Greater subjective distress –Emotional difficulty associated with the transition to adulthood

The Brain in Adolescence Areas of the brain involved in emotional regulation are still growing/changing – Poor self-control; seek rewards and pleasure – Seek novelty; increased risk-taking

“Sex Drive” in Men and Women How is “sex drive” measured (Baumeister, 2001)? –Spontaneous thoughts about sex –Frequency and variety of sexual fantasies –Desired frequency of sexual intercourse –Desired number of partners –Desire for various sexual practices –Initiating sex –Making sacrifices for sex

Sex Drive: Heredity vs. Environment Most research: both heredity and environment influence sex drive –Biological component: androgens (testosterone) plays a key role in sex drive –Cultural and historical context shape sexual attitudes and behaviors

Sex Drive in Men and Women Do men and women differ *on average* in the strength of sex drive? –Many sexuality textbooks suggest that there is no gender difference in sex drive –Baumeister (2001) concluded a meta-analysis: men have a greater sex drive than women

Sex Drive Men think about sex more often than women (Laumann, 1994) Male college students reported more intrusive, unwanted, and personally unacceptable sexual thoughts than college women (Byers, 1998)

Sex Drive Desire number of sexual partners (Buss, 1993): –Women hoped to have 1 partner over the next two years; men hoped to have 8 partners over the next two years –Women desired 4-5 partners over their lifetime; men desired 18 partners

What sex drive does not measure Sex drive does not indicate sexual enjoyment or sexual desire

Limitations to Research on Sex Drive Based on broad averages; does not indicate individual differences and diversities Outliers may skew the data Response bias Social desirability