Dr. Roth divides them into three groups: The first he classifies as 'psychologically healthy,' people who grow up in an environment where it is fine to steal or kill. The second type is the mentally disturbed criminal who looks at his world as threatening. And the third group consists of pure psychopaths.
There are three theories that view the psychological explanation behind a criminal's behavior. The first of which is The Rational Choice Theory. The Rational Choice Theory suggests that the criminal is completely rational when making the decision to commit a crime (hence the name Rational Choice). However, there are many reasons that can result in crimes, but they can mainly be based on greed, revenge, anger, jealousy, or vanity. Classical criminology observes that "people have free will to choose criminal or conventional behaviorsand that crime can be controlled only by the fear of criminal sanctions (Siegel). Another theory is the Eysenck's Theory of Personality and Crimes, which suggests that "criminal behavior is the result of an interaction between certain environmental conditions and features of the nervous system" (Bartol & Bartol, 2005). The theory also proposes that each individual offender has a unique neurophysiological makeup that when mixed with a certain environment, therefore, can't help but result to criminality. Eysenck was not suggesting that criminals are born, but that the combination of environment, neurobiological, and personality factors give rise to different types of criminals. Although there is a lot of research that opposes the theory, researchers believe that if new data were modified the theory, as a whole may still be helpful. .
The final theory is a more extreme version of Eysenck's theory. The trait theory argues that criminality is the product of unusual biological or psychological traits. Each criminal has a unique set of characteristics that explain behavior.
