Children's vulnerability reflected in genes: Some children more sensitive to their environments, for better and worse

Depiction of neglected lonely child (stock image).

Some children are more sensitive to their environments, for better and for worse. Now Duke University researchers have identified a gene variant that may serve as a marker for these children, who are among society's most vulnerable.

"The findings are a step toward understanding the biology of what makes a child particularly sensitive to positive and negative environments," said Dustin Albert, a research scientist at the Duke Center for Child and Family Policy. "This gives us an important clue about some of the children who need help the most."

Drawing on two decades worth of data on high-risk first-graders from four locations across the country, the study found that children from high-risk backgrounds who also carried a certain common gene variant were extremely likely to develop serious problems as adults. Left untreated, 75 percent with the gene variant developed psychological problems by age 25, including alcohol abuse, substance abuse and antisocial personality disorder.

The picture changed dramatically, though, when children with the gene variant participated in an intensive program called the Fast Track Project. After receiving support services in childhood, just 18 percent developed psychopathology as adults.

"It's a hopeful finding," Albert said. "The children we studied were very susceptible to stress. But far from being doomed, they were instead particularly responsive to help."

Previous research has suggested that while some children thrive like dandelions in a wide range of circumstances, others are more like orchids who wither or bloom in different environments. The new study suggests that children's different levels of sensitivity are related to differences in their genomes.

The study appeared online today in the Journal of Policy Analysis and Management.

This is the latest finding from the Fast Track Project, a multi-faceted intervention for aggressive first-graders that ran for a decade at sites in North Carolina, Tennessee, Pennsylvania and Washington state. Beginning in 1991, researchers screened nearly 10,000 kindergartners for aggressive behavior problems, identifying nearly 900 who were at high risk, and assigning half of that group to receive intensive help. It was the largest violence-prevention trial ever supported by the National Institutes of Health and researchers have now followed participants since the early 1990's.

Previous research has linked participation in Fast Track interventions to lower rates of psychiatric problems, substance abuse and convictions for violent crime in adulthood.

The new study looks at the possible biology behind those responses. Albert said these findings could be a first step toward potential personalized treatments for some of society's most troubled children. Knowledge like this might someday be used to help match children who would benefit with programs they badly need.

Key questions remain though, Albert said. For starters, while the Fast Track Project was offered to children of all races, the new findings were limited to white children. Specifically, the authors observed strong response to Fast Track among the 60 white children with a common variant of the glucocorticoid receptor gene NR3C1, a gene involved in the body's stress response.

Although children of other ethnicities benefited from Fast Track, the authors have not yet found a similar genetic clue to help identify which of these children responded most positively to the intervention.

"That doesn't mean such genetic markers don't exist among children of other races," Albert said. "We simply don't know yet what those markers are."

That's one of several important avenues for future research, Albert said, adding that thoughtful examination of the ethical issues involved is needed before the findings can be translated into policy.

"It would be premature to use this finding to screen children to determine who should receive intervention," Albert said. "A lot more work needs to be done before we decide whether or not to make that leap."

Selengkapnya »»  

Neuroscientists identify brain mechanisms that predict generosity in children

Children were monitored with EEGs while watching animated characters perform prosocial and antisocial behaviors, and later participated in a task measuring generosity.

University of Chicago developmental neuroscientists have found specific brain markers that predict generosity in children. Those neural markers appear to be linked to both social and moral evaluation processes.

There are many sorts of prosocial behaviors. Although young children are natural helpers, their perspective on sharing resources tends to be selfish. Jean Decety, the Irving B. Harris Professor of Psychology and Psychiatry, and Jason Cowell, a postdoctoral scholar in Decety's Child NeuroSuite lab, wanted to find out how young children's brains evaluate whether to share something with others out of generosity. In this study, generosity was used as a proxy for moral behavior. The paper is published online by Current Biology and will appear in the Jan. 5, 2015 issue.

"We know that generosity in children increases as they get older," said Decety. He added that neuroscientists have not yet examined the mechanisms that guide the increase in generosity. "The results of this study demonstrate that children exhibit both distinct early automatic and later more controlled patterns of neural responses when viewing scenarios showing helping and harmful behaviors. It's that later more controlled neural response that is predictive of generosity."

The study included recording brain waves by EEG and eye tracking of 57 children, ages three to five, while they viewed short animations depicting prosocial and antisocial behaviors of cartoon-like characters helping or hurting each other. Following that testing, the children played a modified version of a scenario called the "dictator game." The children were given ten stickers and were told that the stickers were theirs to keep. They were then asked if they wanted to share any of their stickers with an anonymous child who was to come to the lab later that day.

The children had two boxes, one for themselves and one for the anonymous child. In an effort to prevent bias, the experimenter turned around while the child decided whether or how much to share. On average, the children shared fewer than two stickers (1.78 out of 10) with the anonymous child. There was no significant difference in sharing behavior by gender or age. The authors also found that the nature of the animations the children watched at the outset could influence the children's likelihood of behaving in a generous way.

The study shows how young children's brains process moral situations presented in these scenarios and the direct link to actual prosocial behavior in the act of generosity by sharing the stickers. "The results shed light on the theory of moral development by documenting the respective contribution of automatic and cognitive neural processes underpinning moral behavior in children," Decety concluded in the paper.

The developmental scientists found evidence from the EEG that the children exhibited early automatic responses to morally laden stimuli (the scenarios) and then reappraised the same stimuli in a more controlled manner, building to produce implicit moral evaluations.

"This is the first neuro-developmental study of moral sensitivity that directly links implicit moral evaluations and actual moral behavior, and identifies the specific neuro markers of each," said Decety. "These findings provide an interesting idea that by encouraging children to reflect upon the moral behavior of others, we may be able to foster sharing and generosity in them." Decety added that these findings show that, contrary to several predominant theories of morality, while gut reactions to the behavior of others do exist, they are not associated with one's own moral behavior, as in how generous the children were with their stickers.

Decety and Cowell are now conducting similar work with even younger children, ages 12 to 24 months, to look at when these neural markers for generosity emerge.

Selengkapnya »»