Science without Sex Essentialism? As Easy as 1, 2, 3!
Over the course of nearly a decade, the GenderSci Lab (GSL) has developed incisive analyses, approaches, frameworks, and methods for thinking critically about sex and gender in biomedicine. Our new article “Three Maxims for Countering Sex Essentialism in Scientific Research” in the journal Biology of Sex Differences synthesizes lessons from GSL research into concrete and portable recommendations for biomedical researchers. Through the examples of gender/sex disparities in adverse drug events, COVID-19, and anterior cruciate ligament (ACL) injury, we offer guidance for avoiding the pitfalls of sex essentialism and producing better science. The article is designed for researchers, reviewers, and editors aiming to produce more rigorous science as well as for instructors and students at the undergraduate or graduate level interested in exploring common problems in sex essentialist research.
What is sex essentialism?
By sex essentialism, we mean the practice of assuming that any disparity between men and women is caused by sex-related biology. Under a paradigm of sex essentialism, any difference found between women and men is understood primarily as a biological difference, regardless of the quality of evidence. This assumption leads to findings that are routinely underpowered, unreplicated, or uninterpretable. Furthermore, sex essentialism often obfuscates the role of gendered social factors that may serve as a more explanatory causal factor than sex-based biology.
“Sex essentialism is a subset of biological essentialism that assigns causal primacy to sex-related biology in explaining disparities between women and men.”
Like other forms of unrigorous scientific research, sex essentialism has serious social implications. Contested claims about sex differences are cited to fuel stigma against LGBTQ and gender nonconforming people, have resulted in sex-based pharmaceutical dosage practices that can result in possibly dangerous over- or under-dosing, and contributed to an overfocus on developing specialized sex-based products rather than addressing structural inequity.
In our article, we outline ways that we have found useful for ameliorating the problems of sex essentialism when researching sex and gender. As sex difference research expands under institutional mandates like the US National Institutes of Health (NIH) Sex as a Biological Variable (SABV) policy and the recently-released UK-based Medical Science Sex and Gender Equity (MESSAGE) framework, there is an increasing demand for methodological guidance. Researchers, instructors, and students across diverse scientific backgrounds often ask: How can we do sex difference research right? Adding to the lab’s prior work articulating “Sex Contextualism” as an alternative to sex essentialist approaches, to answer this, here we offer three practical maxims to promote more rigorous and precise research.
1. Practice responsible citation
The first maxim to counter sex essentialism is to practice responsible citation. As of 2025, an article published in Nature during the height of the COVID pandemic that claimed to find sex differences in immune responses to COVID was cited over 1,500 times. A critical response published in the same journal that demonstrated that the findings did not in fact support a sex difference claim has been cited fewer than 50 times. Despite serious critiques, the original claim of sex difference circulated without acknowledgement of potential methodological flaws. Researchers should ascertain the origin and quality of the evidence underlying a sex difference claim and ensure that contested claims are not presented as settled fact.
2. Consider alternative hypotheses
The second maxim is to consider alternative hypotheses. The claim that female athletes tend to have higher rates of ACL knee injuries has often been attributed to biological and physiological sex differences between men and women. However, alternative hypotheses may also examine gender-related social factors (such as disparities in training resources or access to sports as children) and their impact on differential injury rates. Instead of defaulting to sex-essentialist explanations, researchers should consider the influence of gendered disparities and other gender-related social factors spanning from the individual to the structural level.
3. Mind the denominator
The third maxim is to mind the denominator. If you simply count up the occurrences of adverse drug events reported in the US Food and Drug Administration Adverse Event Reporting System, it may appear that women experience adverse drug events at higher rates than men. This conclusion, however, does not take into account the fact that, in the United States, women are more likely to take medications than men. This may lead to numerically more women reporting adverse drug events but not necessarily higher rates of experiencing adverse drug events. Researchers should always properly define their denominator when making sex comparisons to ensure that gendered differences in exposure and participation are taken into account.
“To move the future of evidence in sex and gender science forward, there is a need both to accelerate the consideration of social variables in research on biomedical sex disparities and to address unfounded, misleading, and tangibly harmful inferences in sex differences science.”
We hope that these three maxims will raise the standard of evidence in sex difference science. By practicing responsible citation, considering alternative hypotheses, and minding the denominator, researchers can avoid the common methodological issues associated with sex essentialism and produce scientific findings more likely to stand up to scrutiny.
Read the open access article here: Boulicault, M., Gompers, A., Aalami, L., Danielsen, A. C., Dore, E. C., Homan, P., Lee, K. M. N., Miyagi, M., Niederriter, H., Sanogo, A., Sudai, M., Thinius, A., and Richardson, S. S. Three maxims for countering sex essentialism in scientific research. Biol Sex Differ 16, 83 (2025). https://doi.org/10.1186/s13293-025-00748-x
Statement of Intellectual Labor
Ben Maldonado and Hannah Niederriter drafted and edited the blog post. Sarah Richardson provided feedback and comments.
SUGGESTED CITATION
Maldonado, B. and Niederriter, H., (2025). Science without Sex Essentialism? As Easy as 1, 2, 3! Gendersci Lab Blog. https://www.genderscilab.org/blog/science-without-sex-essentialism-as-easy-as-1-2-3.