“The question of sex differences in cognitive ability (or intelligence) is a very old one, but it is still hugely controversial. Are there any mental abilities where females outperform males, or vice versa? If so, which abilities? And, perhaps most importantly, why? In this talk, Stuart Ritchie will discuss the science of sex differences in cognitive abilities, covering the controversy, the evidence, and the counterarguments. He will discuss the strengths and weaknesses of the research on cognitive sex differences, consider what sex differences—if they are real—might mean for society, and report on some entirely new data that inform this important, but extremely divisive, question.”