Just when we thought the nature-versus-nurture debate concerning sexualorientation was leaning toward nature--with the search for a "gay gene" ongoing--here comes a new theory of sexual development from Cornell University psychologist Daryl Bem, Ph.D.
Despite the finding that at least one part of the brain is larger in heterosexual men than in gay men, Bern believes biological factors such as hormones, genetic makeup, and brain anatomy don't influence our sexual preferences directly but rather determine our temperament. And temperament, in turn, influences the activities and playmates children prefer.
So while an aggressive boy might relish rough sports, a girl with a gentle disposition may prefer hopscotch. And just as these two will feel different from each other, so too will a rough-playing tomboy feel different from girls who prefer Barbie dolls. Bern says that feeling unlike your same-sex peers makes you perceive them as "exotic," producing physiological arousal--faster heartbeats, increased blood pressure--that's later transformed into sexual attraction. As Bern puts it, "the exotic becomes erotic."