Sexual Identity, Orientation: Age 12–19

A part of discovering one's total identity is the firming of sexual orientation, or sexual, emotional, romantic, and affectionate attraction to members of the same sex, the other sex, or both. A person who is attracted to members of the other sex is heterosexual. A person who is attracted to members of the same sex is homosexual. Many use the term gay to refer to a male homosexual, and lesbian to refer to a female homosexual. A person who is attracted to members of both sexes is bisexual.

In the 1940s and 1950s, Alfred Kinsey and his associates discovered that sexual orientation exists along a continuum. Prior to Kinsey's research into the sexual habits of United States residents, experts generally believed that most individuals were either heterosexual or homosexual. Kinsey speculated that the categories of sexual orientation were not so distinct. On his surveys, many Americans reported having had at least minimal attraction to members of the same gender, although most had never acted out on this attraction. In short, Kinsey and colleagues brought to the attention of medical science the notion of heterosexuality, homosexuality, and bisexuality all being separate but related sexual orientations.

The etiology of heterosexuality, homosexuality, and bisexuality continues to elude researchers. Today's theories of sexual orientation fall into biological, psychological, social, and interactional categories.

Biological theories

Attempts to identify the specific physiological causes of homosexuality have been inconclusive. Traditional physiological theories include too little testosterone in males, too much testosterone in females, prenatal hormonal imbalances, prenatal biological errors due to maternal stress, differences in brain structures, and genetic differences and influences.

Psychological and social theories

Early childhood seems to be the critical period in which sexual orientation forms, suggesting that learning plays a part in causing homosexuality. Freudians have traditionally held that homosexuality is rooted in early childhood developmental conflicts, particularly the Oedipal conflict. Freudians believe homosexuality develops in response to troubled family relationships, an overly affectionate and dominant mother and a passive father, and/or the loss of one or both parents. However, these theories cannot explain why homosexuality occurs in individuals not coming from these types of families.

More recently, researchers have proposed that social‐learning factors may be account for homosexuality. The sexual preference may develop when a child engages in early cross‐gender behaviors (behaviors stereotypical of the other sex) or when a teenager's sexual drive emerges during a period of primarily same‐gender friendships.

Interactional theories

Proponents of the interactional theory of homosexuality allege that sexual orientation develops from a complex interaction of biological, psychological, and social factors. John Money explains that prenatal hormones first act on the embryo's and fetus's brain, which creates a physiological predisposition toward a particular sexual orientation. During early childhood, social‐learning factors influence the child, either facilitating or inhibiting the predisposition.