  Feminist philosophers of biology, such as Bleier (1984) and Fausto-Sterling (1992), reveal a series of problems with studies that purport to find sex differences in brain anatomy, brain lateralization, and hormones that are correlated with gender differences in behavioral traits and abilities. These critiques include pointing out that (1) for most of the behavioral traits in question there is more overlap than difference among populations of men and women, (2) these studies are often based on limited data and insufficient sample sizes, (3) these studies often involve unwarranted extrapolation from rodent models to humans, (4) there are problems with the biological conversion of androgens to estrogens in the body that make it difficult to interpret in vivo experiments, and finally (5) there is also a tendency to discount social causes of putative differences between the sexes (see also Fehr 2004).