A new study of children shows that problematic behavior can be identified in infancy, if not before, by looking at their background and circumstances
In 25 years of clinical practice as a psychologist I’ve seen my share of aggressive boys. They ended up in my office because they kicked classmates, poked children with scissors or, in one unforgettable case, set another student’s collar on fire to get his attention. (It worked.) These boys were usually between the ages of 4 and 10, and most of them came from chaotic homes with few clear expectations, closely spaced siblings and an overwhelmed mother. The father was often absent, literally or psychologically. They had been referred by their teachers, who wanted the aggression to stop.
It was a tall order, and I was only successful some of the time. Now I know that intervention should have started much earlier. A new study published in the JAMA Network in December suggests that children who are most likely to be aggressive throughout childhood and adolescence can be identified in infancy, if not before, by looking at their family histories.
The longitudinal study, led by Richard E. Tremblay of Université de Montréal, followed the development of 2,200 randomly selected babies born in Quebec in the late 1990s, using reports from parents, teachers and the children themselves. In a previous study, the research team found that many children try to use physical force during their first two years of life, by hitting, biting or kicking others. Normally, such aggression peaks between 2.5 and 3.5 years old, and then peters out as children mature and gradually learn society’s rules for social interaction—just in time for them to enter school.
But aggression persists in a small group of children, and the study suggests that they often share a similar home environment. “Children who show problems early are from very specific families,” said Prof. Tremblay. The predictors include one or both parents having been physically aggressive as children or having failed in school. This background is likely to keep families trapped in a dysfunctional cycle. “If you’re physically aggressive and you fail in school, the likelihood of getting a job to get out of poverty is almost nil,” Prof. Tremblay explains.
“These chronically aggressive families could be identified by obstetricians.” Prof. Tremblay says, “so interventions can start close to conception. Starting that early would have a much better impact than waiting until a child is in school.” Yet most aggressive children aren’t identified until they start kindergarten. Teachers are left to wonder, “Why didn’t the parents tell me this child has a problem?”
The answer to that question is one of the study’s most intriguing findings. Unusually aggressive boys were seldom identified by their mothers early on, the researchers discovered. Even if these boys were poised to hurt others and struggle in school, they had to wait for teachers to take note in order to get assistance. In contrast, mothers are more likely to get help for girls, who at any age are far less likely to be physically aggressive than boys.
Whether due to helplessness or denial, this blind spot can be remedied. Some states already offer support such as nurse-family partnership programs, which match vulnerable first-time mothers with registered nurses who visit them up to 60 times during pregnancy and in the child’s first years of life. The nurses offer solid, nonjudgmental advice on subjects like breastfeeding, communicating and bonding with infants and, if necessary, how to quit smoking or drinking.
Through this ongoing relationship, these mothers learn how to sustain a healthy pregnancy and respond to their developing child before he becomes intransigently aggressive, not after. Prof. Tremblay thinks that is wise. “You have to invest in prevention based on the known predictors in the family, and not wait until the second, third or fourth child is born.”