This involves the observation of facts in relation to phenomenon of crime and interpreting them in relation to the possible causes of criminal behaviour. Under physical sciences, a cause-effect relationship can be easily established. For example, a particular factor (i.e. cause) leads to a particular change (i.e. effect) e.g. heal (cause) makes the wax melt (effect). Unlike physical sciences, no causes can be attributed to any criminal behaviour which may be both sufficient and necessary. For example, none of the factors like poverty, age, sex, etc., which may be relevant in interpretation of criminal behaviour, is either sufficient or necessary for commission of crime.
An illustration to make clear the distinction between necessary and sufficient cause - If result B invariably follows cause A whatever else may or may not happen, A would be a sufficient, but not always a necessary cause. If, however, B follows A only if A and certain other factors present, then A is a necessary, but not a sufficient cause. If B invariably' follow A without any other factors required, and A cannot be replaced by any other alternative, then A is both necessary and sufficient cause. This is the reason why no particular crime or criminal behaviour in general can be explained by one cause alone, nor it can be said that a particular cause shall always lead to a particular criminal situation.
Thus, the correlation between observed facts and situations does not always mean that there is a nexus or connection between them. The correlation between a fact and a situation may exist by chance only, and may not occur after sometime. The human behaviour is too complex to be explained by causal approaches or correlation between-a cause and a behaviour pattern.
Crime is a variable concept changing from place to place and time to time and therefore scientific criminal behaviour is impossible. Crimes are like any other social phenomenon which have no stable unit. The latest trend to explain criminal behaviour is to take into account various factors 'like physical, social, economic, etc., i.e. an eclectic view.
Courtesy:- Legal Point Foundation