Like all of culture, stereotypes have to be learned. But once they are, they are extremely difficult to purge from one’s mind, or even to subdue into cultural curiosities that have no power over our behavior or thinking. Neuroscientists have long known that it takes much longer to unlearn incorrect information than it takes to learn it in the first place. Holding on to stereotypes is especially easy because evolution wired us to look for patterns as a survival skill. Successful hunting, gathering, farming and escaping predators all rely on forming patterns from our observations.