Complexity Explorer Santa Few Institute

Our brains have mechanisms by which they classify the world, grouping similar entities, including people, into categories. These categories - stereotypes - allow the brain to make assumptions about any individual in the same group, reducing the amount of information the brain needs to store. (Generally, "stereotypes" refers to groups of people, whereas "categories" refers to groups of non-people entitites, but the concepts are roughly the same and are used below interchangeably.)

For example, how do we stereotype apples? We might an "apple" category in our brains. Within the "apple" category, there might be sub-categories for green, yellow, pink, and red apples, but overall, we make the assumption that everything contained in the "apple" category is a round, hard-but-not-a-rock object roughly the size of a fist and probably has a relatively sweet flavored, pale yellow fruit inside an edible peel. We assume it has a (relatively) inedible core that contains seeds, and those seeds, if planted in a temperate climate, would grow into a tree, and that tree would bear fruits very similar to those that are already in our mental "apple" category. There might be exceptional apples about which we remember specific details or create additional sub-categories: apples with holes or worms or those that are small or sour. But when we come across a new apple-looking thing, we access the mental "apple" category and have a general understanding of what this new entity will be like without having to investigate every single detail.

The alternative, without broad categories (stereotypes), would be to treat every single apple as an individual entity that needs to be understood. Is it a fruit? Is it sweet? Can I eat it? What's inside? Where did it come from? Essentially, the apple stereotype was the downfall of the fairy tale heroine Snow White, who did not expect an apple to make her sleep forever because "poisonous" was not a description associated with her mental "apple" category.

While the efficiency provided by stereotypes is necessary to free our brains to process more complex and changing inputs, categories can be misleading or even maladaptive if the descriptors are not accurate. In the case of the "apple" category, if we had experienced only green apples and refused to believe that any red, hard, round, fist-sized object that came from a tree in temperate regions could be eaten, we'd miss out on a lot of potential nutrients. Our brains need to be able to update stereotypes based on new evidence. When speaking of stereotypes about groups of people, inaccurate category descriptions or a lack of updating can be especially harmful on both sides of the equation.