ABSTRACT
Science is carried out by scientists, and scientists are themselves human. History is littered with examples of human reasoning biases infiltrating the scientific enterprise. At times in human history, egocentric assumptions and self-interest led scientists to posit that Earth is the center of the universe that some races are genetically inferior to others, or that female hysteria is a constitutional disorder. The term “essentialism” is used loosely and variously to cover a range of concepts that are importantly distinct from one another. At heart, essentialism is a realist assumption about categories. Just as individual objects, for example, a squirrel, a diamond, are assumed to be natural entities that exist in the world, discontinuous with their surroundings and independent of own thoughts or existence, so too are categories. Essentialism is core to how adults and children alike construe a range of categories in the natural world.
