Crime has existed for thousands of years, but research and theories into crime as a 'science' have only emerged within the last couple of centuries. There are many factors and influences that may lead up to any individual committing a criminal act, whether they be biological, psychological, sociological, cultural or gender based. Any one of these factors are necessary to induce conditions for the existence of a crime, typically, criminological research tends to focus on one or two factors instead of analysing them as a multi-factored simultaneously. Early criminologists such as Beccaria, (1738-1794) and Bentham (1748-1832) sought to explain crime within the classical school of criminology, focussing on the individuals' need for 'pain' or 'pleasure' and seeing behaviour as rational and self-interested in the pursuit of this. A second approach to the problem of crime was within a biological context, suggesting that physical and biological traits were to blame for criminal behaviour (Lombroso.
1835-1909) and that human anthropology could show a genetic correlation between individuals and criminal acts. In the early 20th century, research into criminal behaviour moved away from the physical/biological approach and started to concentrate on the psychological factors and mental processes that influenced criminals. Freud identified that the conflict between the unconscious drives (id, ego and super ego) could result in criminal behaviour and Eysenck devised a form of personality testing that sought show a correlation between personality and criminal behaviour. It seems that so far much of the research into criminology has leant towards the genetic side, assuming that criminal behaviour is innate and looks for causes of crime ( individual positivist), internally, within the criminal. This assumption was questioned by Sutherland (1947) who moved towards a more sociological approach, believing that criminal behaviour is acquired and learnt by external social factors (sociological positivist).