Sexual activity studies often miss prostitutes

By Pam Sowers
HS News and Community Relations

A UW survey has found that studies about human sexual activity leave out an important factor: the sexual activity of prostitutes.

Men have consistently reported more sexual partners than women did in surveys conducted around the world over the past 15 years. Dr. Devon Brewer, research scientist at the UW’s Alcohol and Drug Abuse Institute, is lead author of a report published in the Oct. 10 edition of the Proceedings of the National Academy of Sciences.

He and his colleagues analyzed data from national sex surveys and studies of prostitutes and their clients. This showed a sampling bias that explains the widely observed difference between the number of sexual partners reported by heterosexual men in contrast to the number reported by women. The researchers found that women working as prostitutes were under-represented in the national surveys.

“Generally speaking, sampling procedures used in these surveys exclude the lodgings where women working as prostitutes tend to live, like motels, rooming houses and homeless shelters,” Brewer said. “Once the prostitutes’ high number of sexual partners was factored in, the discrepancy disappeared.”

Brewer added that the role of prostitution in the statistical discrepancy was not readily apparent because men have been reluctant to acknowledge that their partners included prostitutes.