Many rules that are not written are called customs. Customs are not necessarily the law but it is customary to follow these rules. When a norm is broken, deviance is created. Deviant behavior not only violates the norm but disrupts the established order and causes negative reactions on the part of those who witness it. The most basic level of maintaining the norm through social control would be to mock or make the deviant uncomfortable. Many different causes have been attributed to criminal and deviant behavior. The classical school of criminology states that criminal behavior occurs because the reward outweighs the risk of getting caught. By collecting crime statistics and data, Adolphe Quetelet found that poor young adult males commit crimes more than any other type of crime.