Essentialist Reasoning about the Biological World

Essentialism is the idea that certain categories, such as “dog,” “man,” or “gold,” have an underlying reality or true nature that gives objects their identity. Es-sentialist accounts have been offered, in one form or another, for thousands of years, extending back at least to Aristotle and Plato. Where does this idea come from? I address this question from a psychological perspective and argue that essentialism is an early cognitive bias. Young children's concepts reflect a deep commitment to essentialism, and this commitment leads children to look beyond the obvious in many converging ways: when learning language, generalizing knowledge to new category members, reasoning about the insides of things, contemplating the role of nature versus nurture, and constructing causal explanations. I suggest that chil dren have an early, powerful tendency to search for hidden, non-obvious features of things. Parents do not explicitly teach children to essentialize; instead, during the preschool years, children spontaneously construct concepts and beliefs that re flect an essentialist bias. I explore the broader implications of this perspective for human concepts, children's thinking, and the relation between human concepts and the biological world.