…First, stereotypes are not bugs in our cultural software but features of our biological hardware. This is because the ability to stereotype is often essential for efficient decision-making, which facilitates survival. As Yale psychologist Paul Bloom has noted, “you don’t ask a toddler for directions, you don’t ask a very old person to help you move a sofa, and that’s because you stereotype.”
Our evolutionary ancestors were often called to act fast, on partial information from a small sample, in novel or risky situations. Under those conditions, the ability to form a better-than-chance prediction is an advantage.