U. ROCHESTER (US) — Whether a child confronts new situations in a cautious and submissive way or a bold and assertive one is linked to a hormonal response to stress.
According to a new study published in the journal Development and Psychopathology, the differences may provide children with advantages for navigating threatening environments.
“Divergent reactions—both behaviorally and chemically—may be an evolutionary response to stress,” says Patrick Davies, professor of psychology at the University of Rochester and the lead author of the study.
“These biological reactions may have provided our human ancestors with adaptive survival advantages. For example, dovish compliance may work better under some challenging family conditions, while hawkish aggression could be an asset in others.”
This evolutionary perspective is counter to the theory that there is one healthy way of being and that all behaviors are either adaptive or maladaptive.
“When it comes to healthy psychological behavior, one size does not fit all,” says Melissa Sturge-Apple, assistant professor of psychology. The findings “give us insight into how basic behavioral patterns are also chemical patterns.”
To understand the role of stress in children’s reactions, the researchers focused on parental conflict in young families, looking at 201 two-year-old toddlers from impoverished families with similar socio-economic profiles. Children’s exposure to levels of aggression between parents was based on interviews and questionnaires with the mothers.
“Research has shown that exposure to repeated aggression between parents is a significant stressor for children,” Davies says.
The researchers also documented the dove or hawk tendencies of the toddlers in a variety of unfamiliar situations. Children who showed dovish tendencies were vigilant and submissive in the face of novelty. The toddlers clung to their mothers, cried, or froze when encountering new surroundings.
Hawks used bold, aggressive, and dominating strategies for coping with challenge. They fearlessly explored unknown objects and new environments.
When the children were exposed to a mildly stressful simulated telephone argument between their parents, distinct patterns of hormonal reactions emerged.
Children exposed to high levels of interparental aggression at home showed different reactions to the telephone quarrel. Doves with parents who fought violently produced elevated levels of cortisol, a hormone that is thought to increase a person’s sensitivity to stress. Hawks from such stressful home environments put the breaks on cortisol production, which is regarded as a marker for diminishing experiences of danger and alarm.
The high-and-low-cortisol reactivity provides different developmental advantages and disadvantages.
Heightened cortisol levels characteristic of the doves were related to lower attention problems but also put them at risk for developing anxiety and depression over time. By contrast, the lower cortisol levels for hawks in aggressive families were associated with lower anxiety problems; but these children were more prone to risky behavior, including attention and hyperactivity problems.
Dante Cicchetti, professor of child development and psychiatry at the University of Minnesota, contributed to the research, which was supported by the National Institute of Mental Health.
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