The first hypothesis suggested that both were the result of underlying genetic factors. Using a sample of twins, they found, however, that just 27 percent of the overlap was due to common genetic factors, but that 71 percent was due to common environmental factors the twins shared. Thus, the researchers developed their next hypothesis: that reading and behavior problems were linked to factors in the home environment.
But when they sought to identify those factors - testing whether a stimulating home environment, child neglect, the mother's reading skill, parental income, education and social class, deprivation, family size, maternal depression and/or young maternal age could account for the relation between reading problems and behavior problems - they found the environment alone was not enough to explain the link.
Their third hypothesis, however, that reading problems and behavior problems cause each other, turned out to be correct for boys. For girls, however, the researchers found that while behavior problems lead to reading problems, reading problems do not lead to behavioral problems.
Their finding contrasts with earlier work identifying an overlap between reading problems and attention deficit hyperactivity disorder (ADHD), which was best explained by the influence of common genetic factors. Instead, the findings published in Child Development show that behavior problems and ADHD symptoms should not be considered equal, at least in terms of their connection with reading problems.
"These findings may help guide interventions by showing that targeting either reading problems or behavior problems during the preschool and early primary school years is likely to produce changes in both behaviors," said lead author Kali H. Trzesniewski, Ph.D., of the Institute of Psychiatry at King's College London. "Although this is not necessarily easy to achieve, several studies illustrate the positive affect academic interventions can have on children's antisocial behavior."
Summarized from Child Development, Vol. 77, Issue 1, Revisiting the Association Between Reading Achievement and Antisocial Behavior: New Evidence of an Environmental Explanation from a Twin Study. By Trzesniewski KH, Moffitt TE, Caspi A (King's College London and University of Wisconsin-Madison, Taylor A and Maughan B (King's College London). Copyright 2006 The Society for Research in Child Development, Inc. All rights reserved.