Bisexual attraction study upends decades of flawed research

In 2005, a New York Times headline covering research by J. Michael Bailey, a professor at Northwestern University, read "Straight, Gay or Lying? Bisexuality Revisited." At that time, Bailey incorrectly concluded that bisexual men do not exist.

Flash forward to 2020, and Bailey is still a controversial figure doing research on attraction and sexual orientation. But after 15 years and an overhaul of flawed science, a new story is being told — and Bailey's new work proves he was wrong before.

His co-authored paper, published Monday in the journal PNAS, uses the reported sexual experiences of more than 500 men as well as hard metrics on physical attraction to investigate bisexual orientation in a lab. This paper reviewed 8 earlier studies and found that men who identified as bisexual were both subjectively and genitally, more aroused by both sexes compared to men who report only being aroused by one sex.

Though the team's research has reported the opposite in the past, this new analysis is far more definitive than previous work, says Doug VanderLaan, an assistant professor of psychology at the University of Toronto, Mississauga who was not involved in this study.

"The statistical analyses were as thorough as one could hope, leaving no question in my mind that the overall pattern observed is one that supports the existence of bisexual genital arousal among bisexually identified men," he tells Inverse.

That said, do we really need science to tell us that bisexuality exists? Jeremy Jabbour, a graduate student at Northwestern and the paper's first author says we don't.

"I know that some of my co-authors think of this as we're proving that bisexual men's orientations are valid and meaningful," he tells Inverse. He's of a different opinion.

"I don't think you have to wait for a scientist to validate you."

"If you identify as bi or pansexual, I don't think you have to wait for a scientist to validate you and tell you that your identity or your lived experience is real," Jabbour says.

Ultimately, the study seems to serve more than one purpose. Maybe it provides hard data for those that require it to prove the existence of bisexuality: That, in itself, is a debated idea. Some bisexual activists support research on bisexual behavior as a way of validating their existence. Others roll their eyes — why do you need a study that proves something so obvious?

It also corrects a flawed historical record that used science to invalidate bisexuality. In that way, this new study is a corrective measure.

Quantifying attraction – Since that 2005 study was published Bailey has collaborated with the American Institute of Bisexuality, who provided funding for this research. John Sylla, the president of the group, is an author on the paper and was involved with writing but not data analysis.

The group also has a history of providing input for study design. Such changes, which were also incorporated into a 2011 study, include advertising the study with online ads for men seeking sex with men and women, as opposed to advertising in solely gay magazines or "alternative newspapers."

That' was just the tip of the iceberg when it comes to methodological issues in prior work, Jabbour says.

"There were some mixed findings over the years, [along with] some methodological problems and some of the past studies, mostly that had small sample sizes, [and] there's been some more arcane problems with quadratic regressions," he explains.

The new PNAS study pulls from 8 studies in the past, pooled the data, and re-performed statistical analyses. That data included both self-report measures and experimental data from penile gauge-based experiments (where arousal is measured in how much penile circumference changes).

"The researchers created the largest dataset possible by combining data from several previous studies, each of which was itself conducted well in terms of experimental design and measurement of self-reported and genital arousal," VanderLaan says.

From there the team looked for patterns between self-reported and genital arousal and the Kinsey scale – a foundational tool used in sexuality research. The Kinsey scale ranges from 0 to 6, where zero indicates an exclusively heterosexual preference, whereas a 6 indicated exclusively homosexual preference.

Bisexual men, with Kinsey scores between two and four in this experiment, showed 3.3 times more genital arousal when presented with erotica from their "non-preferred sex," compared to men who rated themselves a zero or a six. For a man with a 2 on the Kinsey scale that "non-preferred sex" would be another man, for a 4 that would be a woman.

Men who place themselves in the zero or six categories tend to show very little arousal to their non-preferred sex – they were 10.16 times more aroused by their preferred sex, going by the penile gauge measurements. By comparison, the bisexual men were only 2.2 times more aroused by one sex compared to the other.

That difference "strongly confirmed" that bisexual men tend to be more attracted to both sexes than monosexual men, the study team says.

Science and sexuality – Scientific research that has sought to legitimize sexuality — or undermine it — is plentiful.

There have been numerous studies searching for existence "gay gene" or scientific missions to "prove" the existence of bisexuality. That research can help explain trends or offer insight — it's not the ultimate decider of whether or not someone's sexual identity really "exists."

But science is still influential, so if such research is going to be done, it has to be done right. Jabber actually sees this study as an application of better science that validates the Kinsey scale for use in sexual research. VanderLaan notes that it incorporates more robust data. Both of these things give scientists a tool to do better work going forward.

Better findings, and more rigorous tools, have already prompted some to reassess – including the authors of that 2005 paper that suggesting that bisexuality didn't exist.

"We know that they were able to change their mind through the data," Jabbour says, referring to his co-authors. "To me, that's kind of like a powerful message about being able to have good scientific debates."

Ultimately, Jabbour sees this work as a way to use science to explore bisexuality as something that we definitely know exists, even before this study was conducted. Maybe we will learn more because of it, maybe minds will change along the way – hopefully they won't need to be.

Abstract: There has long been skepticism among both scientists and laypersons that male bisexual orientation exists. Skeptics have claimed that men who self-identify as bisexual are actually homosexual or heterosexual. (The existence of female bisexuality has been less controversial.) This controversy can be resolved using objective, genital responses of men to male and female erotic stimuli. We combined nearly all available data (from eight previous American, British, and Canadian studies) to form a dataset of more than 500 men, much larger than any previous individual study, and conducted rigorous statistical tests. Results provided compelling evidence that bisexual-identified men tend to show bisexual genital and subjective arousal patterns. Male sexual orientation is expressed on a continuum rather than dichotomously.