Biology influences children’s responses to life’s stresses

Social scientists often place the blame for childhood problems solely on poor nurturing, but a new study adds to evidence that biology strongly influences whether a child thrives or does poorly in a stressful environment.

Daniel Hart and colleagues followed 138 children for six years. At the beginning of the study, the children were in kindergarten through third grade.

The researchers measured the children’s skin conductance response (a measure of the autonomic nervous system’s reactions to stress) as they watched two films—one with no emotional content and another portraying a frightening fire in a child’s room. They also divided the children into high- and low-risk categories for family stress, based on family income and mothers’ level of education. In addition, the researchers analyzed the children’s personality types and traits (for example, their levels of resilience, emotional negativity, and impulse control). At three follow-up visits, the researchers reassessed the children to see how their behaviors, emotional states, and personality traits changed as they aged.

The researchers report, “The results indicated that children who both had exaggerated skin conductance responses … and were living in families with multiple risk factors were most likely to develop an undercontrolled personality type and to exhibit increases in problem behavior and negative emotional intensity.” Hart comments, “What some kids can shrug off [may] be harmful to others.”