Grandmothers may be more emotionally connected to their grandchildren than to their own sons and daughters, study claims
- Experts scanned brains of grandmothers as they looked at photos of grandkids
- Seeing grandkids activated parts of the brain linked with ’emotional empathy’
- But photos of sons and daughters activated areas linked with cognitive empathy
- Grannies may be hardwired to experience the same emotions as their grandkids
- This may make grannies more effective caregivers when grandkids are young
Grandmothers may be more emotionally connected to their grandchildren than to their own sons and daughters, a new study suggests.
In experiments, US scientists scanned grandmothers’ brains while they were viewing photos of their young grandchildren.
When looking at the photos, brain regions associated with ’emotional empathy’ tended to be activated in the grandmothers’ brains, the researchers found.
Emotional empathy is when we feel the same emotion as another person, such as distress in response to their pain.
In contrast, when looking at photos of their sons and daughters, regions of the brain associated with cognitive empathy were activated.
Cognitive empathy is when you can understand someone else’s feelings, but it doesn’t mean you’re feeling the same thing.
It’s possible grannies are evolutionarily hardwired to experience the same emotions their grandkids are experiencing, as a tactic to help them through the early stages of life when they’re young and vulnerable.
Scientists have scanned grandmothers’ brains while they’re viewing photos of their young grandchildren – providing a snapshot of this inter-generational bond (stock image)
EMOTIONAL VS. COGNITIVE EMPATHY
When looking at the photos, brain regions associated with ’emotional empathy’ were activated in the grandmothers’ brains.
Emotional empathy is feeling the same emotion as the other person, such as feeling distress in response to their pain.
It involves sharing an emotional experience with someone, meaning you’re able to feel what they’re feeling.
It differs to cognitive empathy – when you can understand someone else’s feelings, but it doesn’t mean you’re feeling the same thing.
The new study, conducted by researchers at Emory University, Atlanta, Georgia, is the first to examine grandmaternal brain function.
‘What really jumps out in the data is the activation in areas of the brain associated with emotional empathy,’ said lead author James Rilling, professor of anthropology at Emory University.
‘That suggests that grandmothers are geared toward feeling what their grandchildren are feeling when they interact with them.
‘If their grandchild is smiling, they’re feeling the child’s joy. And if their grandchild is crying, they’re feeling the child’s pain and distress.’
Humans are cooperative breeders, according to the researchers, meaning human mothers get help caring for their offspring, although the sources of that help can vary.
‘We often assume that fathers are the most important caregivers next to mothers, but that’s not always true,’ Rilling said.
‘In some cases, grandmothers are the primary helper.’
In the 1960s, researchers came up with the ‘grandmother hypothesis’ to explain why grandmothers live decades after they’ve stopped being able to reproduce.
The grandmother hypothesis, put forward by evolutionary biologist William Hamilton in a 1966 paper, has been applied to humans and other animals.
Female chimps rarely live past childbearing years, usually into their 30s and sometimes their 40s.
Human females often live decades past their child-bearing years – and that may have begun with our early Homo relatives 2 million years ago.
The grandmother hypothesis says that before then, few females lived past their fertile years.
But changing environments led to the use of food like buried tubers that weaned children couldn’t dig themselves.
So older females helped feed the kids, allowing their daughters to have the next baby sooner.
By allowing their daughters to have more kids, grandmothers’ longevity genes became increasingly common in the population and human lifespan increased.
Evidence supporting this hypothesis includes a study of the traditional Hadza people of Tanzania, where foraging by grandmothers improves the nutritional status of their grandchildren.
Another study of traditional communities showed that the presence of grandmothers decreases their daughters’ interbirth intervals and increases the number of grandchildren.
In more modern societies, evidence is accumulating that positively engaged grandmothers are associated with children having better outcomes on a range of measures, including academic, social, behaviour and physical health.
A 2010 modelling study suggested the hypothesis isn’t plausible, however.
Grandmothers being around to help care for their grandchildren helps increase chances of their grandchildren surviving, the hypothesis argues, which ensures preservation of their genes.
To see how brain activity may be involved, the researchers scanned the brains of 50 grandmothers who were shown pictures of their grandchildren, all between three and 12 years old.
Each grandmother lay in a functional magnetic resonance imaging (fMRI) machine, which measures brain activity by detecting changes associated with blood flow.
As a control, they were also shown pictures of their own son or daughter (the child’s parent), an unknown child and an unknown adult.
Grannies also completed questionnaires about their experiences, providing details such as how much time they spend with grandchildren, activities they do together and how much affection they feel for them.
The scans revealed that viewing grandchild pictures activated areas involved with emotional empathy (insula and secondary somatosensory cortex) and movement (motor cortex and supplementary motor area).
However, when viewing images of their adult child, they showed stronger activation in an area of the brain associated with cognitive empathy (temporo-parietal junction and dorsomedial prefrontal cortex).
The results indicate grandmothers may be trying to ‘cognitively understand’ what their adult child is thinking or feeling and why, but not as much from the emotional side.
‘Young children have likely evolved traits to be able to manipulate not just the maternal brain, but the grand maternal brain,’ Rilling said.
‘An adult child doesn’t have the same cute “factor”, so they may not illicit the same emotional response.’
Also, grandmothers who more strongly activated areas involved with cognitive empathy when viewing pictures of their grandchild reported in the questionnaire that they desired greater involvement in caring for the grandchild.
Interestingly, compared with results from an earlier study of fathers viewing photos of their children, grandmothers more strongly activated regions involved with emotional empathy and motivation, on average, when viewing grandchildren photos.
A grandmother carries her laughing granddaughter outside the tourist hotspot of Yangshou in southern China
Pictured, a functional magnetic resonance imaging (fMRI) device, which measure brain activity by detecting changes associated with blood flow
Future research could look at the neuroscience of grandfathers and how brain functions of grandparents differ across cultures.
It’s relatively rare for scientists to study the older human brain outside of the problems of dementia or other aging disorders.
‘Here, we’re highlighting the brain functions of grandmothers that may play an important role in our social lives and development,’ said co-author Minwoo Lee.
‘It’s an important aspect of the human experience that has been largely left out of the field of neuroscience.’
The study was published in the journal Proceedings of the Royal Society B.
EVEN GIRAFFE BEHAVIOUR SUPPORTS THE GRANDMOTHER HYPOTHESIS, STUDY SHOWS
Female giraffes have evolved to go through the menopause early so they can help care for their grandchildren, a recent study published in Mammal Review reveals.
Elegant females spend up to 30 per cent of their lives in a ‘post-reproductive state’ to help raise successive generations of offspring in later life and ensure the preservation of their genes, the authors claim.
This evolutionary trait is known as the ‘grandmother hypothesis’ and has been used to explain why humans live such a comparatively long time after reproduction.
30 per cent is comparable to elephants and killer whales, which spend 23 per cent and 35 per cent of their lives in a post-reproductive state, respectively.
Read more: Giraffes stop reproducing early to care for grandchildren, study finds
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