Why do humans live past menopause? Fully one-third of the human lifespan occurs after childbearing ceases. Given Mother Nature’s preference for reproduction, what could explain this? [Read more…]
This is the third of four posts celebrating the good news about the way the brain ages.
There’s something called the Grandmother Hypothesis, so named because researchers discovered that chimpanzees lived longer if they were part of a band that included elder females, who helped the mothers find and share food.
Of course, researchers speculate about the application of this hypothesis to humans. One benefit of having elders in the tribe is because at about age forty, people start getting really good at regulating their emotions. According to studies in 2003 and 2004 by MIT researcher Mara Mather:
Although the brain wants to focus on the negative (it’s a survival skill), the aging brain makes a deliberate effort to focus on the positive, which is actually harder. Studies show that emotions grow stronger, not weaker, as people age.
Mather theorizes this positive focus may be an evolutionary trait. When we’re young, we need cautionary knowledge so we focus on threats more, but at older age, we’ve accumulated so much of that cautionary knowledge that we view danger in a more complex fashion.
This ability may have evolved because it works well for the species in general. As we get older, we have more mixed emotions, allowing for a more nuanced response to the world. This slows us down, restricting impulsive acts, and that’s good for individual and group survival. Especially since our world is becoming so much more complicated.
I am convinced that in earlier times women during menopause drifted naturally to the edge of the village, constructed for themselves a very small hut, and with perhaps one animal for company – and one that didn’t talk! – gave themselves over to a time without form, without boundaries. They were fishing in deep waters, reflecting on a lifetime of activity and calling up, without consciously attempting to do so, knowledge that would mean survival and progression of the tribe.
More and more good news:
1. According to the Seattle Longitudinal study, our brains are awesome after forty. Seattle tracked the same 6000 people for forty years, finding that people reached their highest cognitive ability from age forty through seventy. This was in four of six areas: vocabulary, verbal memory, spatial orientation and inductive reasoning.
2. We’re also, in the new century, aging more slowly. Researcher Elizabeth Zelinsky found that her group at age seventy tested similar in cognitive ability to the historic levels of women in their mid-fifties.
3. Here’s another goody for you: There’s a substance called myelin, the fatty outer coating of the trillions of nerve fibers in the brain. The white matter acts like insulation on a wire and makes the connections work. Get this: the development of myelin in the brain area relating to language peaks from the 50s to the 60s (2001, Bartzokis). The insulation allows the neuron to recover faster after signals have been sent and get ready to send the next signal more quickly, giving brain cells what Bartzokis calls greater bandwidth. “As myelin increases, it builds connections that help us make sense of our surroundings.”
I was going to end with a wisecrack like I usually do, but I guess I’d rather get serious. We often feel unhappy about getting older, because we’re moving closer to the Great Beyond. Also, we’re inundated with messages from the media 24/7 saying we’re pointless if we’re not young. It’s easy to fall in line and drink the Kool-Aid.
But once you know about all the brain-benefits of age, you might talk about them more. You might celebrate the good news (“I’m more intuitive at this age. Really!”) and spread it around. It might become common wisdom, and attitudes might begin to change in this youth-obsessed country. Wouldn’t that be the gift that keeps on giving? Like to our kids?
Merry Christmas, my friends. Next week, we’ll talk about how one woman was able to continue thriving mentally until she died, in spite of having severe, advanced Alzheimer’s disease. See you Friday.