LEICESTER, England, Nov. 10 (UPI) -- People with extreme anti-social personalities seek out others like themselves and form gangs, British researchers say.
Dr. Vincent Egan of the University of Leicester and Matthew Beadman of University College London said people with anti-social personalities often act rashly and don't think or care how their behavior might harm others -- and become excluded from school and work because they make for disagreeable and difficult company.
The anti-social struggle to make friends and end up feeling isolated and rejected until they meet peers of a similar character, Egan said.
The researchers gave a range of psychometric personality tests to adult male prisoners and asked about impulsive behavior and feelings of commitment to different social groups.
The study, published in the journal Personality and Individual Differences, found even within a group of prisoners, anti-social personality emerged as a strong indicator of involvement in gangs.
Within a large group of prisoners -- all of whom were anti-social -- the most anti-social were more involved in more crimes and more likely to be in a gang than others.