Kindergarten Conduct Linked to Earning Power as an Adult

How you behave in kindergarten may affect your future earnings as an adult.

New longitudinal research examined the association between six prevalent childhood behaviors in kindergarten and annual earnings at ages 33 to 35 years. The study found that both boys and girls who were inattentive at age 6 had lower earnings in their 30s after taking into consideration their IQ and family adversity. For boys only, individuals who were physically aggressive or oppositional (e.g., who refused to share materials or blamed others) also had lower annual earnings in their 30s. And boys who were prosocial (e.g., who shared or helped) had higher later earnings.

The study, in the journal JAMA Psychiatry, was conducted by researchers at Carnegie Mellon University, the University of Montreal, University College Dublin, Observatoire Français des Conjonctures Economiques, Centre pour la Recherche Economique et Ses Applications, Statistics Canada and Université de Bordeaux.

"Our study suggests that kindergarten teachers can identify behaviors associated with lower earnings three decades later," said Daniel Nagin, professor of public policy and statistics at CMU's Heinz College of Information Systems and Public Policy, who coauthored the study. "Early monitoring and support for children who exhibit high levels of inattention, and for boys who exhibit high levels of aggression and opposition and low levels of prosocial behavior could have long-term socioeconomic advantages for those individuals and society."

The study used data from the Quebec Longitudinal Study of Kindergarten Children, a population-based sample of predominantly white boys and girls born in 1980 or 1981 in Quebec, Canada, who were followed from Jan. 1, 1985, to Dec. 31, 2015. In sum, 2,850 children were assessed. The data included behavioral ratings by kindergarten teachers when the children were 5 or 6 years old, as well as 2013 to 2015 government tax returns when the participants were 33 to 35 years old.

The study sought to test the associations between inattention (e.g., lacking concentration, being easily distracted), hyperactivity (e.g., feeling fidgety, moving constantly), physical aggression (e.g., fighting, bullying, kicking), opposition (e.g., disobeying, blaming others, being irritable), anxiety (e.g., worrying about many things, crying easily), and prosociality (e.g., helping someone who has been hurt, showing sympathy) when the children were in kindergarten and later reported annual earnings to Canadian tax authorities.

The study addressed limitations of prior research by assessing children earlier, including specific behaviors within a single model, so the results could be incorporated more easily into targeted intervention programs. The study also relied on tax records of income instead of adults' self-reported earnings.

Researchers found that boys and girls who were inattentive in kindergarten had lower earnings in their 30s.

"Early behaviors are modifiable, arguably more so than traditional factors associated with earnings, such as IQ and socioeconomic status, making them key targets for early intervention," said Sylvana M. Côté, associate professor of social and preventative medicine at the University of Montreal, who coauthored the study. "If early behavioral problems are associated with lower earnings, addressing these behaviors is essential to helping children — through screenings and the development of intervention programs — as early as possible."

The study's authors acknowledge that they did not account for earnings through the informal economy or for unaccounted accumulation of debt. They also note that because they looked at associations, the study did not reach conclusions about causality.

The research was supported by the Quebec Conseil Québécois pour la Recherche Sociale and the Formation de Chercheurs et l'Aide à la Recherche funding agencies. It also received support from the National Health Research and Development Program, Canadian Institutes of Health Research, and Social Sciences and Humanities Research Council funding agencies in Canada, the Molson Foundation, the U.S. National Consortium on Violence and Statistics Canada.