In both studies, men watched videos of male and female same-sex intimacy while genital sensors monitored their erectile responses. While the first study reported that the bisexuals generally resembled homosexuals in their responses, the new one finds that bisexual men responded to both the male and female videos, while gay and straight men in the study did not.

Both studies also found that bisexuals reported subjective arousal to both sexes, notwithstanding their genital responses. “Someone who is bisexual might say, ‘Well, duh!’” said Allen Rosenthal, the lead author of the new Northwestern study and a doctoral student in psychology at the university. “But this will be validating to a lot of bisexual men who had heard about the earlier work and felt that scientists weren’t getting them.”