Defining and Using Gender/Sex in Human Biology: Where Are We? Where Should We Be?

Sex and gender categories are often used by human biologists in hypothesis generation, research design, data analysis, and interpretation. Many studies in human biology thus differentiate samples by “sex” and/or “gender.” But it is unclear to what extent, if any, these terms are defined or clearly operationalized. Through analysis of recent publications in the American Journal of Human Biology we assessed how these terms are defined and used in human biological research. Through systemic coding of the text of all original research studies published in AJHB in 2023, we identified inconsistencies in the definition and application of these terms. We find that sex and gender are often conflated and often lack a clear definition. In addition, the reader must glean definitions and methods of operationalization. We tie these observations to theories of language as social action— the idea that language represents experience, creates organization, and differentiates. Thus more precise gender/sex language use in research reporting increases precision in science, but also matters for dissemination of human biological research. We discuss pressing opportunities for human biologists to lead translational science writing by moving toward such precise yet nuanced uses of sex and gender in their research reporting.