Just what is it that separates us humans from the animals? It is often said that what makes us different from our furry friends is our distinct social skills, including speech and other sophisticated communication tools as well as the capability for large-scale cooperation.
What’s behind humans’ unique abilities? According to science, the answer is grandmothers. A 2012 study showed that grandmothers are responsible for humans’ increased longevity as well as a number of human traits, including pair bonding, bigger brains, new learning skills and our tendency for cooperation.
How did researchers come to the conclusion that grandma is behind some of humans’ best qualities? Scientists have long questioned the evolutionary purpose of menopause, a life stage not experienced by other primates. Anthropologist Kristen Hawkes came up with the “grandmother hypothesis” to explain this phenomenon. According to the theory, the reason humans have an increased lifespan is because grandmothers are around to help care for the next generation.
To test the hypothesis, researchers simulated what would happen to the lifespan of a hypothetical primate species if they introduced menopause and grandmothers as part of the social structure. While chimpanzees typically live 35 to 45 years, the simulation showed that those who experienced menopause lived well into their 60s and 70s, with 43% of the adult female population eventually becoming grandmothers.
The ways in which grandmothers improve longevity are multi-fold. From an evolutionary perspective, grandmothers were able to collect more food and feed children, allowing mothers to have and care for more children. Today that might translate into grandma bringing over a lasagna so that mom can catch up on laundry.
Grandmothers also help out with social skill development. Grandmas can give children special attention when moms may be too busy with other children, or these days, work and supporting their families. Think of grandmas as a built-in support system.
If you were looking for one more reason to love and thank your grandma, the “grandmother hypothesis” may be it! The best part is the beneficial relationship goes both ways. Research shows that grandparents who babysit are less likely to develop dementia and Alzheimer’s. Hooray for grandmas!