Ignored Babies Develop Stress Response
If a baby is ignored even for a few minutes he won’t remember it later, will he? That’s the question Canadian researchers asked, and the answer may come as a surprise. Psychologists at the University of Toronto Scarborough performed an unusual experiment to test the effects of “emotional deprivation” on six-month-old babies. They asked parents of 30 babies to briefly ignore their six-month-old infants.
They then played with them for two minutes, then ignored them again for two minutes, before playing with them again. Next, researchers took saliva samples from the babies to measure their hormone levels. They found that the emotional response in the infants was immediate, with tests revealing elevated levels of the stress hormone cortisol. To see whether the babies would remember the episode, the infants were brought back to the same experiment room 24 hours later, with the same researchers taking their saliva samples.
Although this time, the parents didn’t ignore their babies, the infants demonstrated a distinct “anticipatory stress response” anyway, showing a marked elevation in cortisol. That suggests that the babies were able to anticipate stress based on the expectations formed from the previous day about how their parents would treat them. Another group of infants who were part of the two-day experiment, who acted as controls and weren’t subjected to the parental-non-responsiveness, showed no changes in their cortisol on either day. But the researchers also found that overall, the levels of stress hormones were lower on the second day compared to the first day, suggesting the babies were able to adapt to the stressor, a finding that the research team found interesting.
Experts say the findings are in line with what is already known about “attachment theory,” the theory that children need a close relationship with at least one primary caregiver in order to develop normally. What remains unknown is whether the memories that trigger the anticipatory stress response are located in the mind or the body.
“It isn’t clear where or how the information is being retained,”
said Megan Gunnar, professor of psychology of the Institute of Child Development at the University of Minnesota.
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