Criminologists devote much research to personal and other factors that many cause crime. Studies in criminology have traditionally emphasized the relationship of biological characteristics to criminal behaviour. Today, criminology places greater emphasis on the social and environmental causes of crime. Therefore social sciences research plays an increasingly important role in criminology.

Some studies concentrate on the connection between crime and biological factors such as brain structure and chemical imbalance. Others emphasize the role that people’s emotions and motives play in criminal behaviour. Many criminologists investigate the relationship between crime and other social problems, including poverty, poor housing and overcrowding

Criminologists also study Penology, the science of the punishment and treatment of offenders. Earlier criminologists began rehabilitation as the treatment for them but it had little success, thus, today criminologists recommend making punishment more certain than ever, bringing people to trial quickly, imposing fair and uniform sentences, and providing prisons that are more humane. Criminologists do not consider criminal investigation techniques as a part of criminology.