QUOTE : On average, the boys were about ten when the study began, and about sixteen when it ended. Decades later, when the boys had grown up and were in their forties and fifties, the notes were studied by a researcher named Joan McCord, who compared the teenage experiences with subsequent adult behavior—in particular, criminal behavior. A lack of adult supervision during the teenage years turned out to be one of the strongest predictors of criminal behavior. The counselors had recorded whether the boys’ activities outside of school were usually, sometimes, or rarely regulated by an adult. The more time the teenagers spent under adult supervision, the less likely they were to be later convicted of either personal or property crimes.