Batting for Both Teams: What's the Deal with Bisexuals, Right?
One of the reasons it has been so hard for scientists to identify truly bisexual men is that they have often recruited predominantly from the gay community for studies of male bisexuality. These studies have also mostly relied on self-identification as bisexual, as opposed to a history of sexual encounters with both sexes. And of course there is the simple fact that while our society is pretty cool with bisexual women (you can watch her make out with chicks and still have a chance to put your cock in her later!), and there is at least a community in which homosexual men can find support and others like them, bisexuality in men is often looked down on by both sides of the homo/hetero aisle. This cultural attitude makes in more likely that many bisexual men will suppress one side of their sexuality to fit in with society and such men will not exactly be eager to come forward for scientific studies on their sexual preferences.
In the more recent study recruited men from the Chicago area over the internet. The key to sample selection in this case is how the men were recruited using the internet. In this case they did not answer advertisements put out by the researchers, but instead were approached by the researchers based on personal ads they themselves had posted. Bisexual men in particular were chosen from ads in which they expressed a desire to have sex with both members of a heterosexual couple. They were also required to have had at least two past sexual partners of each sex and to have been involved in a romantic relationship of at least 3 months in the past with at least one person of each sex. Criteria for hetero and homosexual men were similar, except limited to one sex. This resulted in a sample of 35 bisexual men, 31 homosexual men, and 34 heterosexual men. A small sample size, but if the point is to prove that bisexual men exist then you don't need to demonstrate that they are also prevalent, although it would be interesting to see how common bisexuality actually is. The mean age of the men was 35 and the sample included men from a diverse range of ethnicities.
As in the earlier study, the men were shown erotic videos of both men and women as well as sexually neutral videos. They were asked about their subjective arousal in response to the videos and also had the circumference of their penises measured while watching the video to determine genital arousal (using a MP100 data acquisition unit from BIOPAC systems, in case you're in the market for a genital-arousal measurement device). The men's sexuality was also determined using the Kinsey scale, in which complete heterosexuality is 0 and complete homosexuality is 6. The results of both the subjective and objective arousal patterns were compared to this score. The bisexual men scored an average of 3.1 (standard deviation 0.94) on this scale, whereas the heterosexual men scored an average of 0.34 (s.d. 0.45) and homosexual men scored an average of 5.67(s.d. 0.43). The researchers found that while even bisexual men tended to have a preference for one sex over the other, they were still aroused (by both measures) by the sex that they liked less, whereas heterosexual and homosexual men were only aroused by one sex.
The definition of "bisexual," used in this study is extremely rigorous, given that it required the subjects to not only identify themselves as bisexual but to have had substantial life experience of bisexuality. The selection criteria meant that the majority of the men selected to represent bisexuals fell very close to the middle of the Kinsey scale. It's possible that while some of the men in the earlier studies considered themselves bisexual, they did not in fact have enough experience with both sexes to respond favorably to the stimuli they were presented with. It's also possible that some of them fell somewhere closer to the edges of the Kinsey scale and their preference for one sex over the other was strong enough to be difficult to distinguish from hetero or homosexuals, even though their attraction to both sexes was real. This research shows that it is indeed possible for some men to be aroused by members of both sexes, but it doesn't mean that only people who have actually had sex with both men and women or who like both equally should consider themselves bisexual. The label is a personal one that for some indicates a true attraction to both sexes, for others a stretching of the truth that makes them more socially acceptable, and for still others is a way to express an openness to sexual experiences that they may not have already engaged in. In other words, the specifics vary and anyone who claims to be bisexual should be taken at their word.
Dr. Pisaster has a doctorate in biophysics, not actually anything sexy. She does however enjoy having sex, reading about sex, and talking about sex. Especially when she's had a little whiskey.