From the New York Times:
A kindergarten boy's behavior could predict his income as an adult, a new study has found.
Kindergarten teachers in the poorest neighborhoods of Montreal rated 920 6-year-old boys using scales measuring inattention, hyperactivity, defiant behavior, aggression and prosociality (the tendency to help someone being hurt, stop quarrels or invite a bystander into a game). Researchers then gathered information on earnings from tax returns at ages 35 to 36. The study is in JAMA Pediatrics.