A new study, published in the journal Proceedings B, reveals for the first time a neurological insight into this intergenerational link.

Using functional magnetic resonance imaging (MRI), researchers at Emory University in Georgia, USA, analyzed the brains of 50 grandmothers who were shown images of their grandmothers. children, aged between three and twelve years old.

To compare, they were also shown pictures of children they did not know, of one of their children who had become an adult, and of an unknown adult.

Result: "Faced with the images of their grandchild, they really felt what he felt. When he expresses joy, they feel joy. When he expresses distress, they feel distress," a anthropologist and neuroscientist James Rilling, lead author of the study, told AFP.

"They activate areas of the brain that are involved in emotional empathy, and others in movement," he said.

The same regions of the brain are also activated in that of mothers, which is interpreted as being linked to an instinct that makes them reach out to or interact with their child.

On the contrary, when grandmothers looked at images of their adult child, the activation of regions related to cognitive empathy was stronger - such as seeking to understand what a person is thinking or feeling and why, without generating so much emotional involvement.

These findings could in part be linked, according to James Rilling, to the adorable appearance of children - a phenomenon known scientifically and which is shared by many species in order to elicit a protective response.

First study of its kind

Unlike other primates, in humans mothers are given help raising children.

James Rilling, who had previously conducted research on fathers, wanted to turn his attention to grandmothers, in order to explore a theory in anthropology known as the "grandmother's hypothesis".

According to her, evolution has caused women to live long - and long after they are no longer able to reproduce - so that they can care for subsequent generations.

"This is really the first time that we have looked at (this aspect) of grandmothers' brains", according to the researcher.

Very often, it is rather observed to study diseases such as Alzheimer's.

The study participants came from the Atlanta, Georgia, area and diverse ethnic and social backgrounds.

Comparing his results with those collected from fathers, James Rilling noted that overall, grandmothers activated regions involved in emotional empathy more intensely.

But this is only an average, which can differ between individuals, he stressed.

The scientist also questioned all the participants about the challenges and benefits of being a grandmother according to them.

Differences in opinions with parents about child rearing were the most common.

On the other hand, "we joked that many mentioned the advantage of being able to give back (to parents) the grandchildren, it is not a full-time job," he noted. .

Many also said they felt they could be more present than with their own children, because they were relieved of time and financial constraints.

"Many of them ended up saying they enjoyed being a grandmother more than a mother," he concluded.

© 2021 AFP