Freud also focused on the personality factors; he focused on the human brain and believed that humans are born with insatiable, demanding instincts which he called the I.D part of the brain. As individuals are socialised into the moral standards of their culture they develop what Freud called, the ego, and in maturity they develop the super ego (which is effectively the personality).
He stated that well adjusted people develop strong egos, and that the I.D and the superego are in direct conflict, a rational well-adjusted individual would be able to manage this conflict by allowing the id and the superego expression at appropriate times. This suggests that people who are not well adjusted cannot perform this process and so they become overcome by the insatiable, demanding instincts of the id which may lead them to commit crime.
Freud believed that these processes take part in the unconscious part of the brain, so at a conscious level, individuals are unaware of their influence. It can then be understood that people commit crimes but then they do not really know why as these processes happen in the unconscious, this could be challenged as people generally know when they are engaging in criminal behaviour and generally they know why too.
It is difficult to conclude whether or not Freuds theory is valid as it cannot be subjected to empirical analysis, also his sample was mentally disordered patients so they are not a representative sample of the criminal population.
Freud did find that many people who he deemed to have psychological problems recollected experience of emotional trauma during childhood. This is important when looking at the consequences of deprivation during childhood and can be related to Bowlby's theory of maternal deprivation. Bowlby believed that if a child is unable to develop a 'warm, intimate and continuous' relationship with its mother, then the child would have difficulties forming relationships with other people and would be ate risk of behavioural disorders. He demonstrated this through his '44 Thieves' experiment. he found that 44 out of the 88 clients that he assessed at the child guidance clinic were thieves.
Of this 44 he identified some as 'affectionless psychopaths' because they appeared to have little sense of social responsibility and showed no guilt for crime. Those who had not committed crimes showed no display of anti-social behaviour even though they were emotionally maladjusted; they were not diagnosed as affectionless psychopaths. The 44 that were diagnosed as 'affectionless psychopaths', had experienced early and prolonged separation from their mothers, whereas the others had not experienced such separation.
From these findings it can be ascertained that early separation may be related to later emotional maladjustment, which could lead to criminal behaviour. However it is not completely conclusive as Bowlby did not take into consideration other causes foe the maladjustment, ie the individuals that are living in poor conditions or unsettled interpersonal relationships. So although there may be a correlational link between separation and affectionless psychopathy, he does not prove that there is one causes the other.