Psychological essentialism is the hypothesis that humans represent some categories as having an underlying essence that unifies members of a category and is causally responsible for their typical attributes and behaviors. Throughout the past several decades, psychological essentialism has emerged as an extremely active area of research in cognitive science. More recently, it has also attracted attention from philosophers, who put the empirical results to use in many different philosophical areas, ranging from philosophy of mind and cognitive science to social (...) philosophy. This article aims to give philosophers who are new to the topic an overview of the key empirical findings surrounding psychological essentialism, and some of the ways the hypothesis and its related findings have been discussed, extended, and applied in philosophical research. (shrink)