BIO 301 students often have many questions about sexual orientation.

What Science says about sexual orientation:

1. Sexual orientation may have a genetic basis.
2. Sexual orientation traits begin appearing at about 2 years old.
3. Identical twins are 10 times more likely to share the sexual orientation trait.
4. There is no correlation between sexual orientation and race or culture.
5. 1991 research at Salk Institute finds a homosexual men have a portion of the hypothalamus that is twice as large as heterosexual men. Very small sample size.
6. Most likely there is no single GAY GENE. 7. Most researchers today agree a complex combination of genetics, biology and environmental influences work together to make the determination of sexual orientation.

Kinsey Continuum Scale Averages

The following links may help you understand more about this very complicated topic.

Archives of Sexual Behavior

What is gaydar ?

The Journal of Human Sexuality: The Gay Gene and other topics

The Journal of Homosexuality

Some common questions and answers about sexual orientation

Parents Family and Friends of Lesbians And Gays -- PFLAG

A News Web Site for Gays--The Advocate

Gay and Lesbian Medical Association

Is there a Gay Gene? A great web site to investigate whether sexual orientation is biologically based.