2. The first revolution: positive stress

It is a revolutionary concept,” said Nadal. “Depending on its intensity, how much control the child has over it, and the tools the family provides, stress can have a positive, adaptive effect. Clearly, keeping children in a bubble doesn’t do them any favors. It’s a matter of balance.”

In order to apply this, “The key is understanding the mechanisms that make us more resilient and able to overcome adversity. It seems that better resilience comes from greater work memory and ability to anticipate the future. This is highly necessary in a society that increasingly puts us in stressful situations. However, the tools won’t come from modifying one gene or one environmental situation. We don’t know what they are yet, but we have some ideas.”

These ideas, for now, mainly come from laboratory animals. One of the most remarkable has been known since 1956 and is called postnatal handling, as explained Albert Fernández, ICREA ACADEMIA professor at the Autonomous University of Barcelona. Then, the group led by psychologist Seymour Levine began a series of experiments in Chicago to assess the long-term effects of different early-life experiences. To do so, they put newborn rats into groups. One of them would stay with the rest of the litter and their mother, as normal. Those in another group, however, were put into separate cages on their own for several minutes every day for the first twenty days. Finally, a third group was separated from their mother for several hours each day. As expected, prolonged separation had negative long-term effects. Nevertheless, the results from the short-term separation (handling) group were surprising. Later on, these rats were more able to adapt and several additional studies have shown, in general, that they tend to react better to stress, be less anxious and even have better memories. (Although nuances and areas where it isn’t as positive have also been added.)

This doesn’t mean paternal care isn’t fundamental. Other experiments with rats have also shown that the more affectionate mothers were with their offspring (measured in the number of times they lick them and known as “licking”), the less vulnerable they would be to stress as adults. There is even evidence in humans: maternal support in infancy is associated with greater volume of the child’s hippocampus, a key region of the brain for memory and stress. In Israeli children living in war zones, the risk of posttraumatic stress was inversely proportional to the support and relationship they had with their mothers.

The issue, then, seems to be striking a delicate balance that gives enough affection without being overprotective. The theory, however, is complex. One of the new hypotheses pits the traditional view, which says that an accumulation of significant episodes of stress increases a person’s chances of developing negative consequences in the future, against a new, complementary one: episodes of stress in the early stages of life can help people face similar ones in adulthood. This is known as the “match-mismatch” theory. It is so complex that the two may overlap. As explained Mathias Schmidt, researcher at the Max Planck Institute of Psychiatry in Munich, “Some characteristics could follow different models in the same individual and even have a genetic background,” which would make it difficult to apply a global model.

But these facts are extremely relevant. Not only for an individual but also for their descendants. This is the next (possible) revolution.