Disruptive behaviors in childhood are among the most prevalent and costly mental health problems in industrialized countries and are associated with significant negative long-term outcomes for individuals and society. Recent evidence suggests that disruptive behavioral problems in the first years of life are an important early predictor of lower employment earnings in adulthood. A new longitudinal study examined boys from low-income backgrounds to determine which behaviors in kindergarten are associated with earnings in adulthood. The study concluded that inattention was associated with lower earnings and prosocial behavior with higher earnings.

The study was done by researchers at Carnegie Mellon University, the University of Montreal, University College Dublin, Ste-Justine Hospital Research Center, L'Observatoire Français des Conjonctures Économiques, Centre pour la Recherche Économique et ses Applications, Statistics Canada, and Université de Bordeaux. The research is published in JAMA Pediatrics.

"Identifying early childhood behavioral problems associated with economic success or failure is essential for developing targeted interventions that enhance economic prosperity through improved educational attainment and social integration," explains Daniel Nagin, professor of public policy and statistics at Carnegie Mellon University's Heinz College, who coauthored the study.

The study looked at 920 boys who were 6 years old and lived in low-income neighborhoods in Montreal, Canada, beginning in 1984 and continuing through 2015. The boys' kindergarten teachers were asked to rate the boys on five behaviors typically assessed at that age: inattention, hyperactivity, physical aggression, opposition, and prosocial behavior. Prosocial behavior is social behavior that benefits others, like helping, cooperating, and sharing.

Findings revealed that the teachers' ratings of boys' inattention -- characterized as poor concentration, distractibility, having one's head in the clouds, and lacking persistence -- were associated with lower earnings when the students were 35 to 36 years old. In addition, prosocial behavior was associated with higher earnings; examples of prosocial behavior included trying to stop quarrels, inviting bystanders to join in a game, and trying to help someone who has been hurt.

Both findings took into account children's IQ (assessed at age 13) and their families' adversity (parents' educational level and occupational status. Earnings were measured by government tax return data.

The study found that hyperactivity, aggression, and opposition were not significantly associated with changes in later earnings.

Because the research was observational in nature, causality was not assessed. In addition, the study did not examine earnings obtained informally that were likely not reported to Canadian tax authorities. And because the study focused on boys in low-income neighborhoods, its generalizability to other genders or individuals of different socioeconomic status is limited.

"Monitoring inattention and low levels of prosocial behavior should begin in kindergarten so at-risk boys can be identified early and targeted with intervention and support," suggests Sylvana Cote of the Univeristy of Montreal and the University of Bordeaux, who coauthored the study.