It's a less flattering social trait that's seen in humans, animals and even insects. A means to assert dominance, position, power and status over others. It may also become a hobby, bullying others can kill boredom and provide entertainment for the bully and bystanders. There is also more primitive mechanisms at work, as in casting out weaker subjects to solidify the collective so to speak, it's why certain physical traits can make unlucky persons a target. Chads just have the upper hand in this, but other people bully as well. There is also more subtle and passive bullying that is common at most workplaces.