The Center for Disease Control and Prevention (CDC)  in Atlanta has created a category called “Men who have Sex with Men” (MSM) which includes all men who have sexual activity with other men.  This category was created because there are many men who have sex with men who do not identify themselves as “gay.”  The CDC has expressed concerned because those non-gay MSM have been difficult to access for education related to prevention of HIV and other sexually transmitted diseases.

Several years ago, a team of scientists led by Trevor Hart at the CDC studied a group of gay men in terms of ther sexual role preferences and drew some interesting conclusions about how it related to the gay male self-identity.  The study has produced some controversy, but it is worth taking a look at it:

Top Scientists Get to the Bottom of Gay Male Sex Role Preferences: “Tops,” “Bottoms,” “Versatiles” and others in the study of gay male self-identity

By Jesse Bering

http://www.scientificamerican.com/article.cfm?id=gay-male-sex-roles&print=true