Gay genes, liberals, and the relevance of biology to politics

Liberals embrace the role of genetics in homosexuality, but aren’t so keen on it for other things, such as intelligence. Why?

A study about the genetics of “nonheterosexualtiy” came out in Science yesterday [1]. Its main conclusion was completely unsurprising: the trait they were interested in — whether someone had ever, versus never, had sex with someone of the same sex — is partly heritable (we already knew that), and the underlying genetics is complicated (no one single “gay gene”) [2]. In other words, when it comes to genetics, this trait is like absolutely every other behavioral trait [3].

What’s unusual about this trait is that, whereas liberals don’t like to leave too much room for the role of biology in behavior in general (see e.g. Pinker’s Blank Slate), an exception is made for a handful of traits, most prominently homosexuality. A lead author of the study, Benjamin Neale, explains that a major motivation was generating evidence to use to fight for the equality of the LGBTQIA+ community (here). He quotes the motto of the founder of the first gay rights organization, Dr. Hirschfeld, “through science to justice.”

I love the optimism inherent in this view. The truth will support my favored notion of justice! And the truth will move people to action! Unfortunately, when it comes to the science we are willing to believe, our political ideology can act less like tinted spectacles and more like polarizing sunglasses. Climate change is a case in point. Another battleground through the ages has been our beliefs on what shapes human nature and its manifestations: our propensity for violence, mental illness, our intelligence, our personalities, our underlying motivations. Our beliefs about human nature have a particularly significant link to our political ideologies. At stake is the very scope of what state intervention can achieve, and the role of individual responsibility and blame within our society.

Here’s a standard line of argument to explain the interplay between political ideology and one’s views on human nature. Conservatives see biology as an explanation for why society is stratified and should remain so. Biology thus helps justify the existing social order, and makes their preferred policy of laissez-faire a sensible approach. Liberals (in the US sense), on the other hand, see biological differences between individuals as superficial, and emphasize the impact of social and environmental factors, which can be reset through government intervention.

Why then do liberals embrace the role of genetics in homosexuality? A useful way to refine the model above is to think about three properties when considering a cause: is it internal to the agent? Does the agent have control over it? Is it stable? [4] Liberals are likely to emphasize causes of undesirable outcomes that are external to an individual, over which the individual has little control, and that can be viewed as in some sense temporary or subject to change. The appropriate response is one of sympathy, and action to redress injustices, often through government intervention. Conservatives, on the other hand, tend to emphasize those causes that are internal to an individual, where the individual has control, and which are stable. Here the response that follows is blame. Structural interventions are dismissed as futile and unjustified diversions of resources from the more to the less deserving.

Bernard Weiner’s Causal Attribution model

How are genetic influences on traits and behaviors understood within this model? A case could be made for either lens. I have no control over my genetics, which fits with the liberal/sympathy lens. For example, the oft made argument that it is inappropriate to withhold the benefits of equal treatment under the law to sexual minorities because sexual orientation is something we have no control over. But genetics are stable, which fits with the conservative lens. For example, if a trait correlated with socioeconomic outcome — such as educational achievement — has a large genetic component, then interventions that attempt to intervene to equalize these outcomes are, arguably, pointless.

If sound, this logic suggests that we may be prone to do some cherry-picking when it comes to acknowledging evidence of genetic influences. Does this stand up to the data? A few studies asked the extent to which people thought that differences in traits such as intelligence and success in life were attributable to genes. Two large public surveys did not find significant impact of political ideology [5], but a recent study comparing responses across more fine-grained traits, did find a modest difference [6]. Conservatives put greater weight on genetics for attributes associated to success in life, whereas liberals put greater weight on genetics for things historically associated with stigma, including sexual orientation.

These considerations point to an uneasy relationship between what science — and genetics in particular — uncovers about human behavior, and politics. Several of Neale’s colleagues at his home institution thought the work shouldn’t have been done, on the basis that it risks further marginalizing an already stigmatized and discriminated against community (here, here, and here). They fear the results will be misconstrued. To a large extent, I think they’re picturing how the results might look through the conservative lens. They are doing what bioethicist Erik Parens calls exercising binocular vision: not settling for one lens, but using two in order to bring an issue into sharper focus [7].

I was fairly stunned by the conclusion of the Oxford sociologist invited to comment on the study, Melinda Mills: “Future work should investigate how genetic predispositions are altered by environmental factors”. Fears that this type of work could serve as a jumping off point for a scientifically grounded “cure” for homosexuality, however ill advised and pointless, would seem justified by this comment.

There’s a larger context here. Another motivation given for this research was “the data exists, so it was inevitable someone would look at this; better that it’s the competent, good guys.” This argument hurtles us down the slope of uncovering “the truth” about many aspects of ourselves, whether we or not we want it or are ready for it. That a better understanding of the role our biology plays in our lives will help the liberal cause is a hope, not a given. This is a call to prepare ourselves.

  1. Andrea Ganna et al., “Large-Scale GWAS Reveals Insights into the Genetic Architecture of Same-Sex Sexual Behavior,” Science 365, no. 6456 (August 30, 2019): eaat7693,
  2. The study contained several secondary results: unlike other traits, the underlying genetics for males and females was different; the correlations with fraction of same sex partners were not that high, suggesting no one scale along which sexual behavior can be measured; there were genetic correlations with various mental health conditions. It also does a good job both of qualifying its results, and stressing what they think their study does not show.
  3. Eric Turkheimer, “Three Laws of Behavior Genetics and What They Mean,” Current Directions in Psychological Science 9, no. 5 (October 1, 2000): 160–64,; Christopher F. Chabris et al., “The Fourth Law of Behavior Genetics,” Current Directions in Psychological Science 24, no. 4 (August 1, 2015): 304–12,
  4. This causal attribution model was introduced by Bernard Weiner. See application in Jeremiah Garretson and Elizabeth Suhay, “Scientific Communication about Biological Influences on Homosexuality and the Politics of Gay Rights,” Political Research Quarterly 69, no. 1 (March 1, 2016): 17–29,
  5. Sara Shostak et al., “The Politics of the Gene: Social Status and Beliefs about Genetics for Individual Outcomes,” Social Psychology Quarterly 72, no. 1 (March 2009): 77–93; Elizabeth Suhay and Toby Epstein Jayaratne, “Does Biology Justify Ideology? The Politics of Genetic Attribution,” Public Opinion Quarterly 77, no. 2 (2013): 497–521,
  6. Emily A. Willoughby et al., “Free Will, Determinism, and Intuitive Judgments About the Heritability of Behavior,” Behavior Genetics, October 12, 2018,
  7. Erik Parens, Shaping Our Selves: On Technology, Flourishing, and a Habit of Thinking, 1 edition (Oxford ; New York: Oxford University Press, 2014).

Bioethics, Genomics, and the Diversity of Human Experience