Scientists say they have proven what many people who have been lucky enough to grow up with their grandmothers have always known: our fathers’ mothers have strong parenting instincts and they are predisposed to care deeply for their grandchildren.
A new study released in the Royal Society B on Tuesday is the first to provide a neural look at this treasured intergenerational bond.
Using functional magnetic resonance imaging, researchers at Emory University in the US state of Georgia scanned the brains of 50 grandmothers when they were shown images of their grandchildren, who were between three and 12 years old.
As a form of control, they were also shown photos of unknown children, an adult father of the same sex as their grandchildren, and an unknown adult.
“Areas of the brain that are involved in emotional empathy were captured, and also areas of the brain that are involved in movement and motor simulation and preparation,” James Rilling, an anthropologist and neuroscientist who led the study, told AFP.
“When they see the photos of their grandchildren, they really feel what the grandchild is feeling.. So when the child is expressing joy, they feel that joy. When the child is expressing suffering, they are feeling that suffering. “
The same motor regions of the brain are also turned on in mothers’ brains and are believed to be related to the instinct to hold or approach and interact with a child.
On the other hand, when grandmothers saw images of their adult children, there was a stronger activation of brain regions related to cognitive empathy – which seeks to understand what a person is thinking or feeling and why, without much emotional involvement.
This, according to Rilling, may be related to the cute appearance of children – scientifically known as the “baby scheme” that the youngest of many species share to activate caring responses.
First of its kind
Unlike other primates, humans are “cooperative breeders,” meaning that mothers get help raising their offspring.
Rilling, who had previously conducted similar studies on fathers, wanted to turn his attention to grandmothers to explore an anthropological theory known as the “grandmother hypothesis”.
This hypothesis establishes that the evolutionary reason that human women tend to live long lives – well beyond their own reproductive years – is to provide well-being for their own adult offspring and grandchildren.
Evidence supporting this hypothesis has been found in societies that include the Hadza, a group of hunter-gatherers in northern Tanzania, in which grandmothers fed nutritious tubers to their grandchildren.
The effect has also been observed in other species such as elephants or killer whales, which like humans – but unlike the vast majority of mammals – also experience menopause.
“This is really the first look at grandma’s brain,” Rilling said, explaining that brain scan studies in older people typically focus on probing for conditions like Alzheimer’s.
The grandmothers, who lived in the Atlanta, Georgia area and came from diverse economic and racial backgrounds, also filled out a series of questionnaires.
And the grandmothers who reported a greater desire to be involved in providing care had greater activity in the brain regions of interest.
Finally, when comparing this new study with the results of her previous work with parents, Rilling found that -in general- grandmothers activated regions related to emotional empathy and motivation more intensely.
But he assured that this finding is only average and does not necessarily apply to all individuals.
Rilling also interviewed each of the participants to get an idea of the challenges and rewards of being a grandmother.
“Consistently, the challenge that arose the most was the difference of opinions with the parents regarding the way of raising the grandchildren, their values, and the constant struggle to stay aside on these issues,” he said.
On the contrary, and “with this we were joking, but many of them talked about how to give back to the grandchildren, because it is not a full-time job.”
Many grandmothers felt that they could be more present now that they are relieved of the pressure in terms of time and finances that they experienced when they were raising their own children.
“Then, many of them actually said they enjoyed being grandmothers more than they enjoyed being mothers“, he assured.