A new study from researchers at Northwestern University has shown that men identifying as bisexual do in fact respond sexually to both men and women. This will be unsurprising to bisexual men and indeed the wider population, but it is significant because a previous and much cited 2005 Northwestern study concluded that evidence for male bisexuality was lacking and that bisexual-identifying men may in fact just be closeted homosexuals.
Critics charged the 2005 study failed to use appropriately stringent recruiting criteria because participants were recruited through advertisements in gay-oriented publications and were allowed to self-identify. This, critics say, led to a biased result.
Northwestern’s latest findings however suggest that bisexual-identifying men display clear physical signs of arousal when shown both male and female erotic material.
In the new study, published online in the journal Biological Psychology, the researchers relied on more stringent criteria for selecting participants. To improve their chances of finding men aroused by women as well as men, the researchers recruited subjects from online venues specifically catering to bisexuals.
They also required participants to have had sexual experiences with at least two people of each sex and a romantic relationship of at least three months with at least one person of each sex.
In both [the 2005 study and the latest investigation], 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.”
This is the second study this year to investigate bisexuality among men in terms of their physical responses to erotic stimuli. The study by Archives of Sexual Behavior that was released in March approached the question differently but again found both subjective and physical arousal occurred when men identifying as bisexual were exposed to both male and female erotica. You can read more on that over at the New York Times.
The latest Northwestern study has largely been welcomed by groups representing bisexual men who say it is edifying to have the scientific method confirm what they have known all along. However, critics point out that reducing sexuality to a mere physical response does not illuminate the extremely complex factors that make up sexuality as a whole.
Researchers are also keen to stress that measuring physical responses to erotic stimuli in the laboratory is problematic and does not directly compare to everyday human interaction, though it does still aid our understanding.
The Northwestern University study did not examine bisexuality among women, though this is a subject that has been explored by previous studies. A study released in 2008, for instance, said that empirical data suggests bisexuality among women is a fixed sexuality that is not just a transitional stage between heterosexuality and homosexuality, as had been theorized in the past based on anecdotal evidence.