Stress Harms Infants’ Learning Flexibility


Stephen Luntz

Stephen has a science degree with a major in physics, an arts degree with majors in English Literature and History and Philosophy of Science and a Graduate Diploma in Science Communication.

Freelance Writer

2664 Stress Harms Infants’ Learning Flexibility
Young children's capacity to learn flexibly depends on a low stress environment. Credit: Mariia Golovianko/Shutterstock

Children barely a year old learn differently when under stress, a newly published study suggests, becoming less flexible and creative. Although the study used a small sample and a fairly artificial learning set-up, the work adds to evidence that stressful environments favor repetitive learning over creativity.

Stressful situations are known to make adults act more habitually, holding onto familiar choices even when alternatives would serve them better. Sabine Seehagen of Ruhr University Bochum wanted to see whether the same applies for young children. Naturally, there are ethical limits on how stressful a lab environment can be made for young subjects, but even a situation children encounter often was potent enough.


The “stressed” infants were separated from their parents and familiar toys and were introduced to a strange person and toy. They were then shown two buttons that lit up and made noises when pushed. After being shown that both buttons worked, access to one button was blocked by a screen, leading the children to push the other repeatedly. Eventually the second button became available again, but neither button worked.

A control group got the same buttons, but had played with a parent and their favorite toys beforehand, not a stranger.

The levels of cortisol, a stress hormone, were notably higher in those who interacted with the stranger, and this groups showed other signs of stress, such as crying longer. Previous studies have produced inconsistent results as to whether infants have the same cortisol response to short-term psychological stress as seen in adults. 

Seehagen’s more novel finding, reported in the journal PNAS, is that the stressed children continued to push the button they were familiar with, despite it no longer producing the desired result. More relaxed children, on the other hand, were much more likely to experiment with the button they didn't know, once they established the other one didn’t. For the first twenty seconds the two groups' behavior was quite similar, but subsequently the unstressed infants tried changing buttons, while the stressed ones just kept pushing the one they were used to.


The paper notes, “Infants in the stress condition did not engage to a lesser degree with the buttons during the test nor learn the actions generally more slowly than did infants in the no-stress condition. Thus, the effect of stress on infants’ behavior was highly specific.”

On its own the experiment's power was quite limited, with only 26 infants involved. However, it adds to existing evidence that stressful environments discourage flexible learning. Old style teaching methods where children were encouraged to fear their teachers, or fellow pupils, may have been effective for the rigid rote learning favored at the time, but apparently don’t fit well with a world in which children need to learn to experiment.

While in this case Seehagen’s findings suggest that infants’ learning behavior resembles that of adults, she made headlines earlier this year with the finding that babies were more likely to remember information if they sleep immediately afterward, a situation less well understood in adults.