Frontiers

Stress Test

Associate Professor of Psychology Sara Jaffee investigates early childhood behavior.
September 2012

All parents have experienced it—the temper tantrum at the grocery store, the tears on the first day of kindergarten. What if there was a way to predict behavioral issues and anticipate intervention methods? Sara Jaffee, Associate Professor of Psychology, has been investigating this question for years.

“I’ve always been interested in children’s conduct problems—especially children who are aggressive,” says Jaffee. “I look at the interaction between biological vulnerabilities or biological predispositions that increase the chances a child will become antisocial, particularly when kids grow up in chaotic, dangerous or unpredictable environments.”

Jaffee first examines kids in infancy: their temperament and neurobehavioral profiles, and how they become amplified over time. Children who are born to depressed mothers, for instance, tend to be slightly more difficult to soothe. “Over time you start to see problematic paths diverge,” says Jaffee. “I’ve become interested in what accounts for this, what makes those really very small initial differences become much bigger differences as kids go through childhood and into adolescence.”

“I look at the interaction between biological vulnerabilities or biological predispositions that increase the chances a child will become antisocial, particularly when kids grow up in chaotic, dangerous or unpredictable environments.” - Sara Jaffee

In a recent study, Jaffee investigated the effects of early caregiving on children’s physiological reactivity by the time they were eight to 11 years old. Her team used prior interviews with the parents of the children participating in the study as a baseline for early childhood living environment. The kids were then matched with an online opponent—she hired a child actor who appeared in video messages at the end of each round to taunt the participating child. “We took saliva samples throughout the game to measure cortisol—a stress hormone,” says Jaffee. “In some of the kids, the stress hormones shot up, while others just kind of flatlined. The hyporeactive kids that didn’t react were the ones who had lived in chronically stressful environments with harsh and nonsupportive parenting and severe life events.”

Although this might seem paradoxical—that those kids with behavior issues would be the least physiologically reactive when provoked by another child—Jaffee says there is an explanation. Children who are chronically underaroused are typically ones that engage in risk-taking behaviors later on, as a way of upping arousal. “The school setting isn’t structured in ways that will engage them,” says Jaffee, “so very early on they disengage.”

Next, Jaffee plans to apply the data to try to help children locally, as well as follow up with a study of siblings. “It’s a well-established phenomenon that kids who grow up in the same family environment have very different outcomes,” says Jaffee, “particularly in the context of kids who are growing up in dangerous neighborhoods or with family violence. Some kids succumb to these risks, and others seem to do relatively okay. The question is, why?”