Animals models for the development of human sexuality: a critical evaluation.

Biological explanations of human homosexuality build upon a theoretical framework developed from the study of animals, especially that of rodents. Researchers have constructed a physiological model to explain the origin and development of "masculine" and "feminine" behavior. According to this model hormones acting at critical stages in early development organize cells in key areas of the brain. After puberty these hormonally organized brain regions are purportedly capable of activation by post-pubertally produced circulating hormones. This model of sexual development, called the organizational-activational (O/A) model, has framed research on sexual behavior in animals and animal-based account of human behavior for more than 30 years. However, evidence from a variety of sources has slowly accumulated, requiring modification after modification of the original premise. Continuing to use the organizational-activational model now interferes with the acquisition of new knowledge. I sketch the outlines of an alternative bio-social program for research on the development of sexual behavior in animals.