Freud was both the most influential person in the early field of psychology and a complete nutter who did enough cocaine to kill three horses. His ideas are completely rejected today, but his influence and impact on psychology continues to be felt. He thought crime and all other abnormal behavior was a result of issues or problems in the psychological process of childhood development. Much more popular today is the idea that crime is linked to different personality types, which we have assorted tools to directly measure. The problem is that a lot of these measures are just measures of crime, resulting in criminologists trying to measure the independent variable and the dependent variable the same way (at least partially) so of course a correlation will be found. This is called a tautology.



Trying to implement therapy and other psychological processes to reduce crime has had mixed results. Many times, it was because conclusions either couldn't be drawn at all or were misleading because of assorted issues involved in the implementation of the program designed to administer those treatments. Therapy does seem to have important and robust impacts on some groups of criminals, in some situations.