U.S. study of gay sheep may shed light on sexuality

August 15, 2005

Oregon State University (OSU) animal researchers in conjunction with the U.S. Department of Agriculture's (USDA) Dubois, Idaho-based Sheep Experiment Station released a report on an OSU-USDA study which was initiated in 1995 after breeders asked the government to determine why some rams bought as breeding studs showed no interest in females. The researchers are working under a $2.8 million grant from the National Institutes of Health in hopes of developing a test which can determine the likelihood of a ram being female-oriented before it is sold as a stud.

By studying difference in the animal's brains after slaughter, the study also showed what could be a biological determiner for what makes a ram male-oriented instead of female-oriented sexually. The scientists' results showed that the anterior preoptic area of the rams' hypothalamus was 50 percent smaller in male-oriented rams as opposed to female oriented rams. A 1991 study of human brains of AIDS victims showed a similar hypothalamus size difference between gay and heterosexual men.

The sheep researchers postulate that low levels of aromatase hormones in the brain of a developing male sheep fetus may have kept the brain from fully masculinizing, leading to sexually male-oriented rams.

"This lends further support to the idea that homosexuality has biological underpinnings," Charles Roselli, a professor of physiology and pharmacology, said in an interview with the Corvallis Gazette-Times.

Professor Stormshak believes that "understanding sexual drives and the continuum of sexual behavior could possibly help explain the scientific basis of sexual assault [and] put an end to assertions that homosexuality is a lifestyle choice."