define behaviour using simplistic and deterministic assumptions that may not be applicable in 50 years’ time? The only solution, therefore, is to study behaviour using biological and social assumptions combined to combat the weaknesses of each theory on its own. Many researchers today agree with this and interpret behaviour using a variety of assumptions and study it using alternative methods. Enrico Ferri (1901) emphasises this in a concluding statement, ‘to sum up, crime is a social phenomenon, due to