Academic Freedom Is Social Justice: Sex, Gender, and Cancel Culture on Campus.

I teach in and co-direct the undergraduate program in the Department of Human Evolutionary Biology at Harvard University. During the promotion of my recent book on testosterone and sex differences, I appeared on "Fox and Friends," a Fox News program, and explained that sex is binary and biological. In response, the director of my department's Diversity, Inclusion and Belonging task force (a graduate student) accused me on Twitter of transphobia and harming undergraduates, and I responded.

Testosterone levels and mental rotation performance in Chinese men.

Males achieve markedly higher scores than females on mental rotation tests (MRTs). Therefore, it might be hypothesized that, within groups of males, testosterone levels modulate MRT performance. However, studies of this relationship have yielded inconsistent results.

The relationship of male testosterone to components of mental rotation.

Studies suggest that higher levels of testosterone (T) in males contribute to their advantage over females in tests of spatial ability. However, the mechanisms that underlie the effects of T on spatial ability are not understood. We investigated the relationship of salivary T in men to performance on a computerized version of the mental rotation task (MRT) developed by [Science 171 (3972) (1971) 701].