There is clear evidence that criminals tend to age out. Most serious and violent crimes are committed by people under the age of forty. According to Cathy Widom and Michael Maxfield, the core age for criminal behavior is from twenty to twenty-five. Moreover, Factor 2 on Hare’s Psychopathy Checklist, which measures antisocial behavior, is negatively correlated with age. Thus, there is a general reduction of impulsive-aggressive and reckless behavior as people get older. This reduction may also relate to the fact that older people have less energy and physical vigor than younger people. However, planful criminal behavior that makes minimal physical demands on the criminal is less likely to diminish with age. As Hare’s data shows, the psychopathic personality traits (Factor 1) do not decrease with age but are stable over time. That is why psychopathic people who have underlings to carry out their antisocial behavior, such as murderous dictators and kingpins of organized crime, can continue to engage in criminal activity well into their eighties.