Brain-related sex differences are real and clinically important, but often grossly distorted in public discourse. In this talk, Lise Eliot debunks several popular myths about sex differences in the human brain and their hormonal basis. For example, for most mental traits, male-female differences are smaller than the popular “Mars/Venus” perception and few have been linked to reliable differences in brain structure or activity. Another common misperception is that neural sex differences in brain anatomy, activation, or neurochemistry are necessarily innate or “hardwired.” These notions are dangerous, as they validate stereotypes, bias clinical judgment, and dictate sex-selective educational policies. Eliot is the author of Pink Brain, Blue Brain: How Small Differences Grow into Troublesome Gaps – And What We Can Do About It.