When Do Your Mental Powers Peak in Life?

At what point in your life do different mental powers peak? Some of the earliest intelligence tests simply categorized all people over the age of 16 as "adults." Today, researchers recognize that the brain continues to develop and change throughout early adulthood and that there are significant changes in how the brain functions as people age.

Still, we often tend to think of the adult brain as a relatively stable and unchanging thing, suggesting that various mental abilities are simply static, or even on the decline, throughout most of adulthood. Conventional ideas about intelligence often suggest that people hit their mental peak fairly early in life and then follow a long, slow decline into old age.

There is also a tendency to believe that certain mental abilities, such as fluid intelligence, typically peak relatively early in adulthood. Crystallized intelligence, on the other hand, is often suggested to peak during late adulthood.

According to some experts, this long-held dichotomy might be far too simplistic. Researchers Joshua Hartshorne and Laura Germine utilized a large pool of online participants to gather information about exactly what ages certain mental abilities are the strongest. What they discovered was that there was a surprising consistency to when particular abilities typically peak.

Some Mental Abilities Peak Much Later in Life

According to the study published in the journal Psychological Science, different aspects of fluid intelligence peak at different ages, with some abilities hitting their apex as late as age 40.

“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’ve peaked on most things, much less all of them,” explained researcher Joshua Hartshorne of MIT and one of the study's authors.

Hartshorne had previously found that visual short-term memory peaks in the mid-30s before beginning to go down. In a 2011 study, Germine found that the ability to recognize faces also improves until people are in their early 30s and then begins to gradually decline.

Digging deeper, the two began looking at archival data from older intelligence tests. What they discovered was that there appeared to be no single mental peak. Instead, different abilities seemed to peak at wildly different and sometimes surprising ages. These results helped inspire their further investigation into how mental abilities change with age.

Large Online Samples Offered a Unique Look at Mental Abilities

The latest study was able to draw on a large online sample of participants who utilized the websites gameswithwords.org and testmybrain.org. Using the approach, the researchers were able to gather data from nearly 50,000 people across a wide range of ages. Four different types of cognitive tasks were used as well as one task that looked at the ability to detect the emotional states of other people. Hartshorne and Germine's earlier research had shown that these tasks measured mental abilities that change as people age.

The results revealed what the researchers called "considerable heterogeneity in when cognitive abilities peak."

When Do Mental Powers Peak?

Among the key findings from the latest study and earlier research:

• 18-19: Information-processing speed peaks early, then immediately begins to decline.
• 25: Short-term memory gets better until around age 25. It remains fairly steady until it begins to decline around age 35.
• 30: Memory for faces peaks and then starts to gradually decline.
• 35: Your short-term memory begins to weaken and decline.
• 40s-50s: Emotional understanding peaks in middle to later adulthood.
• 60s: Vocabulary abilities continue to increase.
• 60s and 70s: Crystallized intelligence, or accumulated knowledge and facts about the world, peaks late in life.

While the results that crystallized intelligence peaks later in life are consistent with earlier findings, this study implies that this peak occurs much later in life than previously believed. What could explain this late peak in mental abilities? The researchers suggest that their results might be due to the fact that people today have more education, greater access to information, and more mentally demanding jobs than did previous generations of adults.

The results suggest that while older brains might indeed be slower, they are likely to still be more accurate, knowledgeable, and better able to assess the moods and emotional states of others. The researchers are continuing their online research by introducing more cognitive tasks as well as tests designed to measure language abilities, executive function, and social and emotional intelligence. They also agree that further investigations are needed to determine exactly why mental powers peak at different ages.

"We took the existing theories that were out there and showed that they’re all wrong. The question now is: What is the right one? To get to that answer, we’re going to need to run a lot more studies and collect a lot more data,” said Hartshorne.