E-Mail Babies learn the difference between "us" and "them" fairly early in life. Social categorization -- the process of dividing the world into groups based on features such as gender, race and nationality -- can be a useful strategy when you're new to the world and trying to process a flood of information with your developing brain, according to UC Santa Barbara developmental, evolutionary and social psychologist Zoe Liberman. The act of creating groups -- for instance, all the objects that can be categorized as some type of chair -- serves as an efficient learning tool for minds still learning to grasp the world around them. But what starts out as a useful survival behavior in our early lives could become a problem when it is applied to people: The tendency to form groups and to like people who are more familiar can lead to stereotyping, bias and racism.