Is There A Bi Gene? It Probably Isn’t That Simple


The idea of a single “gay gene” (or any kind of sexuality-related gene—bi, fluid, or straight) has long been considered misguided.  We’ve known for a long time that genes don’t work that way. They aren’t “on” switches for complex attractions and behaviors; differences among people in many genes and many environmental variables jointly lead to differences in their characteristics.

But genes can still affect your biology in ways that may affect the development of your orientation, indirectly. For example, your genes might make you more sensitive to rewarding stimuli at an early age or less sensitive to this kind of stimuli. Either of those things could conceivably change what you pay attention to while you’re growing up, which could potentially shape how your sexuality develops. Genes could also make you more masculine in some ways or feminine in others, which could have significant effects on how you interact with peers, how other people treat you, and the ways you relate to romantic and sexual scenarios.

There are several labs working on studying the relationship between sexuality and genetics. One of those is the research lab of Dr. David Puts at Penn State. I asked Dr. Puts and his research coordinator, Heather Self, to answer some questions on a study they’re currently working on to explore human sexuality using 23andme data. Notably, they’re focusing on bi people (and are still recruiting bi participants).

VK: Few studies on orientation include bisexuals as a population. What understanding are you hoping to gain with your 23andme research by including bisexuals?

Puts Lab (PL): Historically, bisexual people have been socially and scientifically marginalized. Yet, by studying bisexuality, we think that we might be able to clarify a dimension of sexuality than we could not see by comparing people who are exclusively heterosexual or homosexual. In particular, exclusively heterosexual and exclusively homosexual people are similar in an important way: they are attracted only to one sex. We’re interested in what causes some people to be more equally attracted to both sexes. By including participants from this range of sexualities and especially focusing on recruiting bisexual participants, we hope to better understand the similarities and differences.

VK: How likely is it that research on the biology of human sexuality could be used in a way that’s harmful to LGBTQ people? This is a concern some people have expressed.

PL: We view this risk as very low. Some commentators have expressed the concern that knowledge of the genetic basis of sexuality could lead to biological tests that can be used to determine people’s sexual orientation from their DNA without their consent, or to avoid pregnancies that might lead to a non-heterosexual child. If such a test existed, it would likely be regulated due to the ethical implications of its use. However, because many genetic and environmental factors jointly produce variation among people in sexuality, we are also extremely unlikely to identify a single genetic factor that would be useful for these purposes.

VK: Are there any potential benefits that your research has for the sexual orientation populations you study?

PL: Yes, our research may have benefits to sexual minorities. For instance, research shows that people who believe that sexuality is “innate” or “biological” are especially likely to favor equal rights for homosexual and bisexual people. To the extent that we find associations between genes and sexuality, the knowledge of these results may to contribute to decreased discrimination and increased acceptance. In addition, bisexuality has been largely ignored in past sexuality research. Our research will help remedy this deficiency by bringing attention to and understanding of this historically marginalized group. Beyond this, our research may have wide-ranging benefits to human health more broadly—for example, by helping us understand the processes of psychological sexual differentiation. In fact, in 2015, the National Institutes of Health released a notice confirming the importance of considering sex and gender in health-related research. Many diseases, including major psychiatric ones such as depression, anxiety, and autism, differ by sex in severity and/or prevalence, and so it is critical to understand how sex differences, including differences in sexuality, develop.

Something I find really exciting about this kind of research is not just that it can tell us more about bisexuality, but the fact that bisexuality can help us to understand human sexuality more broadly. Bisexuality challenges a lot of assumptions and misconceptions about sexuality and forces people to look deeper. Bisexuality points away from the idea of preferences as clear switches. Fluid bisexuality helps us question claims that orientations are completely fixed. The elements of different people’s bisexual attractions (romantic, sexual, social, aesthetic) help us see the multi-faceted nature of all desire.

Whether or not a study like this finds strong genetic links, it provides valuable information for continuing to understand orientation. It may not be information that tells a neat story, but it can help us consider new questions, with room for different interpretations of whatever patterns show up.

If you have 23andme data and are interested in participating in the study described, please follow this link. It will be open until January 1, 2018.


Victoria Klimaj
Victoria Klimaj studies the neural basis of sexual orientation at Northwestern University. She recently helped to publish the first neuroimaging study of bisexual men and is currently working on a study of bi women. She's interested in cultural conversations about gender and sexuality and thinks we need insights from both the sciences and humanities in order to understand each other and move forward together.