In other words, if they had a conduct disorder and also had acted in some antisocial manner, it was more likely than not that they were psychopaths. In another study, the two factors in young offenders indicative of psychopathy were impulsive conduct problems and callous attitudes. These children develop attitudes of grandiosity and they shun responsibility. They're also susceptible to boredom. To sum this up, childhood psychopathy has proven to be the best predictor of increased antisocial behavior in adolescence, especially in boys who were hyperactive, impulsive, and suffered from attention deficits.
Some psychologists claim that it's mostly learned through cultural images and role models.