'Callous-unemotional' children often grow up to lie, fight, and bully, study finds
Monday, February 21, 2011; 6:01 PM
Children who display a lack of emotions such as guilt and remorse often go on to develop severe behavioral problems such as fighting, lying, and stealing, a first-of-its-kind, long-term study has found.
"We're not suggesting these children are psychopaths," said Nathalie Fontaine of Indiana University in Bloomington. "But these [emotional] traits can identify children at risk for persistent and severe antisocial behavior."
Fontaine presented the study Monday at the annual meeting in Washington, D.C., of the American Association for the Advancement of Science.
The study drew on reports from the parents and teachers of roughly 9,500 twins born in England in the mid-1990s, tracking them at ages 7, 9, and 12.
The most worrisome group of children identified in the study - about 5 percent - rated high on a scale of what psychologists call "callous-unemotional traits" at age 7, then continued to exhibit a disturbing lack of normal emotions through age 12.
These children were also at highest risk for destructive, antisocial behavior, including bullying and having trouble making friends. About 80 percent of these high-risk kids were boys.
However, another group of 7-year-olds - 13 percent of those in the study - who initially rated high on the scale of emotional problems improved significantly. By age 12, they displayed a wider range of normal emotions, including remorse.
Fontaine said child psychologists are now eager to understand what factors - which may include improved parenting - led to the emotional health gains seen in this group.
As for possible interventions for the high-risk group, other research has shown that children who display a lack of guilt and remorse do not improve their behavior when punished. However, there is intriguing evidence that such children respond well - even better than children with more normal emotions - to positive reinforcement.
"Instead of saying, 'You behaved badly today, it's time for a timeout,' it's probably better to say, 'Here's what you did well today,'" Fontaine said.
Patricia Brennan, a psychologist at Emory University in Atlanta who was not involved in the study, said the concept of "callous-unemotional" children was controversial among child psychologists when it first emerged some 15 years ago. In particular, many researchers resisted the notion that children could exhibit the same cold emotions that define adult psychopaths - including those who torture and kill with no remorse.
Since then, though, a growing body of work has linked callous-unemotional traits to behavior problems later in life, Fontaine said. Her study is the largest, most thorough to date.
In a secondary finding, the study uncovered an intriguing but unexplained connection between genetics and the lack of normal emotions in children. Because identical twins share all of their genes, studying them allows researchers to isolate the influence of genes versus the influence of environment.
In boys, the stunted emotional range that preceded trouble stemmed largely from inheritance - that is, the trait appeared to be strongly influenced by the genes parents passed on to their sons. In fact, about 80 percent of the likelihood of boys developing emotional problems were explained by inheritance.
But in the much smaller proportion of girls in the study who lacked normal empathy, inheritance played almost no role.
Brenna called the huge disparity in genetic factors between boys and girls "puzzling." There may have been too few emotionally disturbed girls in the study to provide good data, she said. Alternately, the genes involved in the trait may be located on the X chromosome. Boys only inherit one X chromosome, whereas girls have two, meaning that boys are more susceptible to the influence of inheriting a single copy of an important gene.
Fontaine said her team is now searching for any genes that may be involved in the lack of normal emotions in children.