Debate over the military's exclusion of gay men and lesbians is based on the mistaken assumption that heterosexuals cannot overcome their prejudices, says Gregory M. Herek, UC Davis research psychologist in an article to appear in the May issue of American Psychologist. Based on an extensive review of social science research data, Herek concludes heterosexual military personnel can change their thinking and adapt to living and working in close quarters with homosexuals. Lesbians and gay men are inherently just as capable of military service as heterosexuals, but acceptance of a new policy depends on the public's understanding that openly gay and lesbian personnel won't impair combat effectiveness, Herek says. "In the past, the military has proved itself willing and able to attack prejudice and stereotypes based on race and gender within its ranks. The challenge of the 1990s may well be to continue this tradition by eliminating barriers based on sexual orientation." Herek is scheduled to testify May 5 on the military's policy on gays before the House Armed Services Committee on behalf of the American Psychological Association.