Abstract

This chapter questions the way “sex” features in behavioral ecological research as a standard explanatory variable. Researchers often use sex to explain variation in a trait or phenomenon that they are studying. This practice is widespread, partly because sex is often easy to identify and often explains some variation, thus making it easier to discover and test other causal patterns of interest. Yet, sex also frequently fails to explain variation. Using a couple of recent examples, it is shown how the pervasiveness of sex as an explanatory variable is partly due to the structure of scientific research, including the use of data from large longitudinal studies, and generalization from previous studies. Researchers should more carefully assess and justify the relevance of sex to each new study, to avoid overgeneralization and the perpetuation of assumptions about sexual difference and its importance in biology.