– A new study finds that the way infants are parented, in combination with their physiological response to stress, influences the emergence of behavioral problems later in childhood. Led by University of Maryland College of Education researcher Nicholas J. Wagner, the study looked at how infants’ cortisol levels moderate the effects of parenting behaviors on the development of conduct problems and callous-unemotional traits—a risk factor in adult psychopathy—in childhood.
“Our research helps us to understand the processes through which experiences with parents during infancy contribute to children's behavior problems,” Dr. Wagner said. “With little existing research on how biological stress functioning interacts with early caregiving, this study is an important part of understanding why some children are vulnerable to developing behavioral issues.”
Published in Child Development, the longitudinal study of 1,292 families from rural counties in North Carolina and Pennsylvania examined aspects of mothers’ caregiving of their infants at age six and fifteen months during home visits. Researchers also tested infants’ saliva, both at rest and in response to fear stimuli, for levels of the stress-related hormone cortisol. Upon reaching first grade, the children were assessed for conduct problems like oppositional defiance and callous-unemotional traits, such as caring about getting in trouble and hurting others’ feelings.
Researchers assessed parent-child interaction in terms of maternal sensitivity (e.g. responsiveness to the child), harsh-intrusion (e.g. insensitive behaviors), and mental-state talk (e.g. mothers’ tendency to infer and comment on her infant’s mental state). Infants’ reactivity was determined by examining the change in cortisol levels in response to fear or frustration stimuli.
The study found that experiencing high levels of maternal sensitivity in infancy predicts fewer behavior problems in early elementary school, but only for infants who are highly reactive, or demonstrated a larger than average change in cortisol levels in response to fear stimuli. High levels of maternal harsh and intrusive behaviors in infancy predict less empathy and less helpful, positive behavior in first grade, but only for infants who demonstrate high levels of stress at rest. The study’s findings are in line with other research suggesting that some children are more likely to be affected by their environment.
“For reactive children, highly sensitive mothers help to buffer against future behavior problems, and harsh and intrusive behaviors by mothers may undermine children’s development of empathy and socially acceptable behavior,” Dr. Wagner said.
Dr. Wagner is a postdoctoral fellow in the Department of Human Development and Quantitative Methodology at the University of Maryland College of Education. His research focuses on factors within the family system, such as parent-child interactions, which influence social, emotional, and behavioral development, with a particular focus on how psychopathology develops in children and processes that can affect that development.
Full journal article available: http://onlinelibrary.wiley.com/doi/10.1111/cdev.12900/full.
