WHAT ARE THE CAUSES OF CRIMINAL BEHAVIOUR?Throughout the history people have tried to elucidate the factors that contribute to aberrant social behaviour. For instance, the Puritans in the 17th century believed that those who did not adhere to the rules of social norm were possessed by evil spirits. Therefore, the focus was on the individual rather than ones environment. Thereafter Cesare Lambroso (an Italian criminologist) supported the theory of anthropological determinism. He concluded that criminality was inherited, and that one can identify a potential outlaw by studying his or her physical features. However, in the twenty-first century, research into the factors which explain criminal behaviour has profoundly advanced, and one can assume that there are three main reasons why people commit crime, namely, biological, psychological and social.First, the primary cause of anti-social conduct may be biological. Much research has been done to find out wether a persons genetic make-up could have an impact on his or her chances of committing a crime. And indeed studies suggest that there is a genetic basis for some immoral behaviour. Researchers found that identical twins were twice as likely to have similar criminal conduct, because they have the exact same genetic make-up, than fraternal twins who have similar but not identical genes. Also studies related to brain activity and crime show that outlaws experience less brain reaction to threatening situations than most people, thus they do not fear punishment as much as others. Second, another factor in criminal behaviour can be psychological. A cycle of violence is where people grow up with anti-social demeanour or abuse and in turn they will be much more likely to mistreat their own children, who later, in consequence, may follow the same pattern. Therefore, neglected or abused children tend to be more susceptible of committing crimes later in their lives than others because of the psychological stress.Third, yet another cause of immoral behaviour may be social. Peer pressure is a factor that strongly influences a decision to commit crime. Very often young girls and boys feel constrained to fit into expected standards of their peers and, as a result, the need of fitting in instigates their misdemeanour. Driven by material gain they might join a criminal gang where for immoral behaviour and criminal activity one earns street credibility and respect. Therefore, indeed peer pressure has a vital impact on a person and contribute to the development of anti-social personality disorders.In conclusion, biological, psychological and social factors are the major causes of criminal behaviour. Naturally, the twenty-first century criminologists are looking at a wider range of factors, and usually a combination of many factors is behind a person who commits a crime.Thus studying those factors can help with explaining the causes of criminal behaviour.