Do senior moments mean your mental skills will start to dim like a failing bulb? That they’ll no longer rise to the top of their game—that’s something just for young people, right? Not so fast, says a 2015 study in the journal Psychological Science.
Laura Germine, a post-doctoral in the Psychiatric and Neurodevelopmental Genetics Unit at Massachusetts General Hospital and Harvard Medical School, and Joshua Hartshorne, a post-doctoral in the Computational Cognitive Science Group at MIT, conducted a study with nearly 50,000 online participants to measure cognitive skills of brain processing speed, memory, emotional cognition and crystalized intelligence, the application of learned knowledge such as vocabulary and arithmetic—and received some surprising results.
Studies have shown that fluid intelligence, or short-term memory, peaks in early adulthood, and crystalized intelligence in middle age. But Germine and Hartshorne caution that “most studies of cognitive change are constrained in their ability to detect subtle, but theoretically informative life-span changes, as they rely on either comparing broad age groups or sparse sampling across the age range.”
The researchers tested tens of thousands of volunteers, ages 10 to 89, who visited their websites, gameswithwords.org and testmybrain.org, on memory skills for abstract symbols and digits, problem solving and vocabulary. They compared these results with historic scores from the Wechsler intelligence test and the Wechsler memory subtests, which tap different aspects of short- and long-term memory. They also included a test for emotion perception, based on pictures of cropped faces, which only showed the eyes.
Cognition’s peaks and valleys
The results? While studies have found that many cognitive skills peak in youth and decline with age, with the exception of crystalized intelligence peaking in the 40s, Germine and Hartshorne found: Brain processing speed occurs, as expected, in late teens and early 20s and declines only slowly over time.
Working memory, a system for temporarily storing and managing information required to carry out complex cognitive tasks such as learning, reasoning and comprehension, peaks at around 30 years of age; and social cognition, the ability to detect others’ emotions, peaks even later in the 40s or 50s—and doesn’t start to significantly decline until after 60. And crystalized intelligence? While the Wechsler data suggested that vocabulary peaks in the late 40s, the researchers found that crystalized intelligence, measured in vocabulary skills, continues to improve until about age 65 to 70.
As the Wechsler data were collected two decades ago, however, they note that these new results may stem from an increase in a better educated Boomer populace with more opportunities for mental stimulation.
Aging for the better
Ultimately, Germine and Hartshorne found that “not only is there no age at which humans are performing at peak on all cognitive tasks, there may not be an age at which humans perform at peak on most cognitive tasks.”
In other words, Hartshorne says, “at any given age, you’re getting better at some things, you’re getting worse at some other things, and you’re at a plateau at some other things. There’s probably not one age at which you’re peak on most things, much less all of them.”
And for all you smarty pants seniors? You might want to break out the Scrabble board the next time those know-it-all youngsters visit.