Lead researcher Dr. William Cardasis of the Michigan Center for Forensic Psychiatry said that Antisocial Personality Disorder is a mental disorder characterized by several psychological and behavioral phenomena, including a lack of empathy and remorse, a low tolerance for anxiety and shallowness.

To be diagnosed with Antisocial Personality Disorder, the individual must have developed this behavior before the age of 15, and as such is qualitatively different from the idea of a scheming, dishonest business person or politician, unless the behavior began earlier in life, Cardasis said.

Cardasis said that of the patients studied, 15 had tattoos and 17 were diagnosed as having Antisocial Personality Disorder. Of those with tattoos, 11 of 15, or 73 percent, had Antisocial Personality Disorder, but only six of 21, or 29 percent, of those without tattoos had the same diagnosis.

The study, published in the Journal Personality and Mental Health, also uncovered an increased likelihood for those with tattoos to have previously suffered from sexual abuse, abused substances or to have attempted suicide.