The scientists say they have shown what many people who have been lucky enough to grow up with your grandmothers have always known: the mothers of our fathers have a strong nurturing instinct and are predisposed to care deeply for your grandchildren.
A new study disclosed in the publication Royal Society B Tuesday is the first to provide a neural look at this treasured intergenerational bond.
Using functional magnetic resonance imaging, researchers from the Emory University in the US state of Georgia scanned the brains of 50 grandmothers when they were shown pictures of their grandchildren, who had between three and 12 years old.
As a form of control, they were also shown photos of unknown children, of a adult parent of the same sex as their grandchildren and a 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 also turn on in the mothers brains and they are believed to be related to the instinct to hold a child or approach and interact with them.
On the other hand, when grandmothers saw images of their adult children, there was a stronger activation of brain regions related to cognitive empathy -that seeks to understand what a person is thinking or feeling and why, without so much emotional involvement.
This, according to Rilling, It may be related to the tender 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 previously had conducted similar studies on parents, wanted to focus his attention on grandmothers to explore an anthropological theory known as the “Grandmother hypothesis”.
That hypothesis establishes that the evolutionary reason that human women tend to live long lives – well beyond their own reproductive years – is to give them welfare to their own adult offspring and their grandchildren.
Evidence supporting this hypothesis has been found in societies that include the Hadza, a group of hunter-gatherers from northern Tanzania, in which grandmothers fed nutritious tubers to their grandchildren.
The effect has also been observed in other species such as elephants, or orcas, 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 inquiring into conditions like Alzheimer’s.
The grandmothers, who lived in the area of Atlanta Georgia, and they came from diverse economic and racial backgrounds, they 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 his 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 about 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 you can give your grandchildren back, because it is not a full-time job.”
Many grandmothers felt that they could be more present now that they are released from the pressure in terms of time and finances that they experienced when they were raising their own children.
So many of them actually said they were enjoying being grandmothers more than they enjoyed being mothers, ”she said.