Various theories of sexual development exist, including cognitive-developmental, social-learning, and psychoanalytic theory. Recent empirical evidence has cast some doubt on each, but each is useful in helping us understand how sexuality develops.

First, some definitions, or Gender Concepts:

Sex = biological sex = sex as determined by chromosomes, gonads, internal and external genitalia. This would complete the statement, "I was born a …"

Gender Identity = self image of biological sex. "I think of myself as a …" This is usually consistent with biological sex, but can deviate, e.g., in transsexualism, pseudohermaphroditism. Note that gender identity, the ability to label not only oneself, but others as male or female, develops relatively early.

Gender Stability = child knows that a boy becomes a man and a girl a woman.

Gender Constancy = child knows that gender a function of biology and won't change.

Sexual Orientation = person's preference for persons of same, opposite, or either sex. This involves:

• emotional attachments;
• sexual behavior;
• sexual fantasies.

Much of Freudian theory assumed that most of childhood is "latent" or quiescent sexually from about age 5 through puberty. Empirically, this does not seem to be true.

Friedrich et al, 1991, conducted a community-based survey to determine normative sexual behaviors and thoughts of children. Suspected or known cases of childhood sexual abuse were excluded. The children ranged in age from 2-12. The parents, not the children, were interviewed, however which may have led to underreporting of some behaviors. The results:

• 10% of 7-12 y/o girls talk about sex; 9% of boys this age do;
• masturbation, touching and exposing genitalia, and sex play are common in children;
• no evidence of latency period in sexual development.

Further evidence of this was found in a retrospective study of adult males and females who reported 57% and 48% prevalence of sexual play in childhood (Kinsey, 1948,1953). 85% of female college students in another survey (Lamb and Coakley, 1993) remembered engaging in sexual play, with a mean age of 7.5 years; 85% of these girls were NOT coerced or persuaded.

Some interesting statistics:

• The average age of menarche has moved up from 16.5 years old in 1860 to 12.5 years old today. Combined with a later average age of marriage or starting a family, this creates a relatively prolonged period of adolescent sexual risk.
• In 1979, 66% of 17-19 y/o males stated they had had intercourse, versus 79% in 1991.
• In 1970, 25% of girls aged 15-19 y/o endorsed having had intercourse; in 1990 that figure that climbed over 50%.
• Teenagers today have a higher average number of sexual partners
• although they are more likely to be engaged in multiple serial monogamous relationships than to have multiple simultaneous partners and
• prolonged periods of abstinence are common
• Of sexually experienced males, the average 15 y/o had had intercourse 1.8 times in the past month, whereas the average sexually active 19 year-old had sex 3.5 times in the past month (Source: Seidman and Rieder, Annual Review of Psychiatry, 1995).
• The number of adolescent females with 2 or more sexual partners rose from 39% in 1972 to 51% in 1979 to 59% in 1988.
• Teenagers have their first sexual experience at a younger average age (now 17)
• Teenagers have a high prevalence of masturbation (90% of 13-15 y/o males and 50% of 13-15 y/o females).

The bottom line: if any intervention to decrease rates of teen pregnancy and sexually transmitted diseases is to succeed, it must start early, in the pre-teen years. This contrasts with the reality of the American school system in which sexual education is often inadequate or completely absent, the curriculum maybe hampered or paralyzed by political constraints (usually in combination with some form of denial on the part of both parents and adolescents), and the availability of contraception, especially barrier contraception, is highly variable. One survey indicated only 28% of parents talk to their children about sex. Sexual education must be proactive. Health care providers must bring it up; it is very unlikely that children or adolescents will begin discussing it spontaneously.