Researchers have discovered a there is a genetic link between personality and mental illness. As one of the researchers explained: “Mental illnesses can be viewed as maladaptive or extreme variants of personality traits.” The researchers studied the genetic profiles of 260,000 people focusing on the five long-established personality traits (extraversion, neuroticism, agreeableness, openness to experience and conscientiousness) that are considered the basic categories of personality. What the researchers found was that these personality dimensions when identified on a person’s genome map (yes, there are “personality genes”) strongly correlated to gene variations that predicted various mental illnesses.
Now you might say, “What’s new?” It is observable in our everyday life that people we know who have, for example, a neurotic personality also tend to have anxiety disorders and depression. These links between personality and mental illness have long been observed and studied. What this study reveals however is that there is a genetic link; in other words, it’s not all nurture. The researchers theorize that the personality a person is born with may tip over into mental illness when pushed to extremes by life experiences.
This field of research, which is sure to eventually unlock the keys to mental illness, is a potential minefield in terms of the criminal justice system. It would not be a stretch to say that many criminals are born. In other words, a criminal is born with a certain personality type—as are we all— but the criminal personality is one susceptible to the risk of mental illnesses, such as antisocial disorders or psychopathy. Indeed, it is estimated that more than half of all incarcerated criminals have some kind of mental illness. (Removing the large numbers of persons incarcerated for victimless crimes would increase that percentage substantially.)
California Criminal Defense Lawyer Blog

