(Reuters Health) - Boys whose teachers find them antisocial in kindergarten may have lower income as adults than their classmates who don’t have behavior problems, a Canadian study suggests.

FILE PHOTO: A child's handwriting on a whiteboard is seen in a kindergarten class at Walsh Elementary School in Chicago, Illinois, March 1, 2013. REUTERS/Jim Young

Misbehaving in school has long been linked to lower levels of academic achievement and income in adulthood, researchers note in JAMA Pediatrics. But the current study offers a unique snapshot of this connection by examining behavior assessments done by kindergarten teachers and then looking at students’ earning on tax returns three decades later.

“Kindergarten teacher assessments are good predictors of problems which accumulate over time - behavior problems with peers and adults, school failure, delinquent behavior, substance abuse, etc. - and lead to poor job market integration,” said senior study author Sylvana Cote, a public health researcher at the University of Montreal.

The 920 boys who completed the study earned an average of about US$28,866 a year by the time they were in their mid-30s, with annual income ranging from zero to $142,268.

Rising levels of inattention in kindergarten assessments were associated with $1,295 less in annual income, the study also found. Over 40-year career, the financial effect could amount to about $70,533.

Teacher ratings of hyperactivity, opposition, and aggression didn’t appear to influence earnings later in life.

“Pro-social” behaviors like paying attention and interacting well with classmates, however, were linked with an average increase of $406 in annual earnings.

These results suggest that school-based programs designed to help students improve behavior when they’re young may have lifelong economic benefits, Cote said by email.

“If the school provides adequate support to these children from kindergarten onwards, they will succeed in school and have less problems with substance use and delinquent behavior,” Cote said.

All of the boys in the study were from low-income neighborhoods in Montreal, and researchers controlled for several factors that might independently impact future earnings including parents’ income and education levels, family structure and neighborhood poverty levels.

However, it’s not clear whether results would be similar for students growing up in more affluent neighborhoods or for girls.

The study also wasn’t a controlled experiment designed to prove whether or how teachers’ assessments of behavior might influence adult income.

Teachers may also be biased in their assessments of behavior, said Dr. Caroline Kistin, a pediatrics researcher at Boston University School of Medicine and Boston Medical Center who wasn’t involved in the study.

“Prior research has demonstrated significant differences in how teachers rate child behavior based on child race, gender, and socioeconomic status,” Kistin said by email. “There are also known disparities in how students are treated in school, including who gets placed in separate special education tracks, who is required to repeat a year of school, and who gets suspended.”

Disparities in how students of color are treated in school can also start before kids even reach kindergarten, particularly for black males, Kistin said.

“Parents, teachers, and medical providers should work together to improve communication around child development and social skills, with a focus on early, supportive interventions when there are concerns,” Kistin advised.

To succeed in school and later in life, students need support that goes beyond the classroom.

“Communities should invest in evidence-based preventive services that have been shown to improve outcomes for low-income children and families, including access to food resources, affordable housing, and high-quality, affordable childcare,” Kistin added.

SOURCE: bit.ly/2E3wlB7 JAMA Pediatrics, online February 11, 2019.