Characteristics that distinguish one family from another, rather than children's genetic traits, most strongly predict whether adults or others physically punish or abuse them, according to a study published last month in the APA journal Developmental Psychology (Vol. 40, No. 6). However, the study reveals a key distinction: While children's genetic temperaments appear to play little to no role in abuse of children, temperament does appear to significantly influence whether parents or others physically punish them.
In other words, children genetically prone to misbehave more often spur parents to strike them than do their mild-tempered counterparts--but such genetic differences between children hold no such sway over their chances of being abused, says lead author Sara Jaffee, PhD, a psychology professor at the University of Pennsylvania.
The finding gets at an age-old question of whether it's something about the child, or something about the parent, that leads to child maltreatment, Jaffee notes. Her team's finding supports the latter.
"There's been a blame the victim--"kid asked for it"--theory posed, and this suggests that's not going on," she explains. "Children's noncompliant, antisocial behavior can explain why they might get spanked, but not physically abused."
To reach that finding, Jaffee and her team tapped a British 1994-1995 birth cohort of 1,116 twin pairs and their families, all participants in the Environmental Risk Longitudinal Twin Study. The researchers began by interviewing mothers of the 5-year-old twins to gauge whether children had been punished corporally, through spanking or slapping. Researchers judged whether children had been physically abused based on mothers' reports about injuries children sustained during discipline and whether social services had ever contacted the family about the child's welfare. The researchers also used mother and teacher reports to pinpoint children's engagement in bullying, fights, lying, stealing and other such antisocial behavior.
Finally, the researchers tested for genetic influences by comparing the experiences of monozygotic twins, who share all their genes, and dizygotic twins, who share considerably fewer genes. The analysis revealed that while environment accounted for most of the variance in twins' exposure to physical punishment, genetically influenced traits like antisocial behavior accounted for at least a fifth of it: Those genetically inclined to be antisocial were physically punished, but not necessarily maltreated, more often.
In their analyses the researchers did not, however, tease apart physical punishment frequency and severity--something that warrants future study, says Jaffee. The fact is, she notes, more than 90 percent of parents have hit their children at least once by the time their children are 3 or 4 years old. And she expresses concern that factors such as a parent's own abuse experiences or financial difficulties could cause "normal range" corporal punishment to slip into abuse.
To prevent that skid, she recommends parenting interventions that help parents increase children's compliance without resorting to spanking. Also helpful, she notes, are home-visiting programs that reduce parents' stress and actual or potential child abuse.
--B. MURRAY LAW