It has long been believed that an individual becomes violent due to a traumatic childhood, characterized by abandonment and abuse. Others have argued that people become violent because they are mentally unbalanced. Over the years, many studies have been conducted to discover the causes that push a person to become a serial killer, but there is still no definitive cause. All serial killers are psychopaths (people with a psychopathic personality, manifested by amoral and antisocial behavior, lack of ability to love or establish meaningful personal relationships, extreme self-centeredness), but not all psychopaths end up being serial killers. However, there are traits common to all psychopaths. These common traits include genetics and environment. While a psychopath's personal experience and environment play a role, studies show that genetic abnormalities or dysfunctions of the brain play a huge role in creating a killer. Culture versus nature has been a topic of debate for some time when it comes to serial killers. One of the most interesting studies on the question of whether traits are the result of nurture or nature comes from the Minnesota Study of Twins Reared Apart. This study was conducted by Professor Thomas Joseph Bouchard Jr. of the University of Minnesota. The study evaluated identical twins who were separated at birth and raised in different families. The study found that an identical twin raised apart from their co-twin was as likely to be similar to each other in personality, interests and attitudes as a twin raised in the same household with their co-twin. A pair of twins in Bouchard's study attracted worldwide attention. Nicknamed the “Jim twins,” these twins were adopted at the age of four weeks... middle of paper... June 2010. Web. April 10, 2014. .Kent A. Kiehl, Alan T. Bates, Kristin R. Laurens, Robert D. Hare, Peter F. Liddle. “Brain Potentials Imply Temporal Lobe Abnormalities in Criminal Psychopaths.” Journal of Abnormal Psychology (2006): 115-118. Proquest Criminal Justice Database.Minnesota, University of. Minnesota Study of twins reared apart. 4 September 2007. Web. 10 April 2014. .Thomas J. Bouchard, Matt McGue, Yoon-Mi Hur, Joseph M. Corno. “A Genetic Environmental Analysis of the California Psychological Inventory Using Adult Twins Raised Separately and Together.” European Journal of Personality (1998): 307-320. Document. unknown. Socially challenging. November 11, 2010.web. April 10th 2014. .