"In other words, the lowest levels of antisocial behaviour are found in kids whose parents start and stay in the highest income bracket while their kids grow up," says Dr. Lisa Strohschein, author of the study and sociologist at the U of A.
While the findings show that the effects of low income at an early age on antisocial behaviour--conduct such as bullying, being cruel, breaking things, cheating or telling lies--persist as kids get older, depression seems to have the opposite effect. The effects of starting off in a low-income household on child depression lessen as time goes on, regardless of later income levels. The research is published in the current issue of the "Journal of Health and Social Behavior."
"These findings might mean that antisocial behaviour is an example of biological embedding--it is possible that poverty early in life helps to set into motion a consistent pattern of antisocial behaviours that are difficult to change once learned," says Strohschein. This finding supports at least one developmental theory that posits that early childhood constitutes a sensitive period of development in which insults suffered during this time are likely to have long lasting effects on child development.
Strohschein used the data from an American survey, the Child Supplement of the National Longitudinal Study of Youth, to study the mental health status of more than 7000 children. Between 1986 and 1998, more than 3300 mothers reported on the health of their kids--aged four to 14--and were reinterviewed up to six times during that span.
She also found that changes in income are associated with changes in child mental health. If household income improves after early childhood, child mental health improves. Conversely, drops in income increase depression and antisocial behaviour.
However, Strohschein notes that the effects of these income histories on child mental health are not large. "It may be that the things that are associated with loss of income such as parental divorce and unexpected job loss are much more important. In the future, it will be important to explore how such events intersect with income loss to affect child mental health."