This is the kind of study that can give people some itchy feelings. We’ve known that early behavior can predict later success, remember the famous Marshmallow experiment, but those studies often had limitations. Was it caused by innate intelligence? Was it caused by the family background? This new study claims to have bypassed these limitations due their longitudinal design and how they tried to correct for both IQ and family background. My impression is that – just like the Marshmallow experiment before – this study show the importance of executive functions in life, besides elements that are rather related to personality. The key question that remains: can we work on this with lasting effect (check e.g. this). Oh, and this kind of research can also be misused. The horror if people would think that they could predict the future of an individual based on this.
Question Are behaviors in kindergarten associated with employment earnings 30 years later, after controlling for child IQ and family background?
Findings In this study of 2850 participants who were followed up for 30 years, inattention at age 6 years was found to be associated with lower annual earnings at age 33 to 35 years, after adjustment for IQ and family adversity. For male participants only, aggression-opposition was associated with lower annual earnings and prosociality was associated with higher annual earnings.
Meaning Kindergarten teachers can identify behaviors associated with lower earnings 3 decades later; early monitoring and support for children exhibiting high inattention, aggression-opposition, and low levels of prosocial behaviors could have long-term socioeconomic advantages for those individuals and society.
Taken from the press release:
Researchers have examined what childhood behavior can tell us about how individuals will do economically later in life. But the methods they used to reach an answer were limited, which tempered the studies’ findings. New longitudinal research that addressed these limitations examined the association between six prevalent childhood behaviors in kindergarten and annual earnings at ages 33 to 35 years. The study found that individuals who were inattentive at age 6 had lower earnings in their 30s after taking into consideration their IQ and family adversity. For males only, individuals who were physically aggressive or oppositional (e.g., who refused to share materials or blamed others) had lower annual earnings in their 30s. And males 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 Franc?ais des Conjonctures Economiques, Centre pour la Recherche Economique et Ses Applications, Statistics Canada, and Universite? de Bordeaux.
“Our study suggests that kindergarten teachers can identify behaviors associated with lower earnings three decades later,” says Daniel Nagin, professor of public policy and statistics at Carnegie Mellon University’s Heinz College, 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 January 1, 1985, to December 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.
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, and relied on reports from teachers instead of self-reports by children and 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. They also found that boys who were aggressive or oppositional at age 6 had lower earnings, and that boys who were prosocial at age 6 had higher 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,” explains 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.
Abstract of the study:
Importance Specifying the association between childhood behaviors and adult earnings can inform the development of screening tools and preventive interventions to enhance social integration and economic participation.
Objective To test the association between behaviors at age 6 years and employment earnings at age 33 to 35 years.
Design, Setting, and Participants This study obtained data from the Quebec Longitudinal Study of Kindergarten Children, a population-based sample of boys and girls (n = 3020) born in 1980 or 1981 in Quebec, Canada, and followed up from January 1, 1985, to December 31, 2015. The data included behavioral ratings by kindergarten teachers when the children were aged 5 or 6 years and 2013 to 2015 government tax returns of those same participants at age 33 to 35 years. Data were analyzed from September 2017 to December 2018.
Main Outcomes and Measures Mixed-effects linear regression models were used to test the associations between teacher-rated inattention, hyperactivity, aggression, opposition, anxiety, and prosociality at age 6 years and reported annual earnings on income tax returns at age 33 to 35 years. Participant IQ and family adversity were adjusted for in the analysis.
Results The study included 2850 participants, with a mean (SD) age of 35.9 (0.29) years, of whom 1470 (51.6%) were male and 2740 (96.2%) were white. The mean (SD) personal earnings at follow-up were US $33 300 ($27 500) for men and $19 400 ($15 200) for women. A 1-unit increase in inattention score at age 6 years (males mean [SD], 2.47 [2.42] vs females mean [SD], 1.67 [2.07]) was associated with a decrease in annual earnings of $1271.49 (95% CI, −1908.67 to −634.30) for male participants and $924.25 (95% CI, −1424.44 to −425.46) for female participants. A combined aggression-opposition score (males mean [SD] 2.22 [2.52] vs females mean [SD], 1.05 [1.73]) was associated with a reduction in earnings of $699.83 (95% CI, −1262.49 to −137.17) for males only, albeit with an effect size roughly half that of inattention. A 1-unit increase in prosociality score (males mean [SD], 6.12 [4.30] vs females mean [SD], 7.90 [4.56]) was associated with an increase in earnings of $476.75 (95% CI, 181.53-771.96) for male participants only. A 1-SD reduction in inattention score at age 6 years would theoretically restore $3077 in annual earnings for male participants and $1915 for female participants.
Conclusions and Relevance In this large population-based sample of kindergarten children, behavioral ratings at 5-6 years were associated with employment earnings 3 decades later, independent of a person’s IQ and family background. Inattention and aggression-opposition were associated with lower annual employment earnings, and prosociality with higher earnings but only among male participants; inattention was the only behavioral predictor of income among girls. Early monitoring and support for children demonstrating high inattention and for boys exhibiting high aggression-opposition and low prosocial behaviors could have long-term advantages for those individuals and society.