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When Does Your Intelligence Peak?

Are we really at our smartest in our 20s? What about the wisdom and experience that come with age? At what age do we strike the right balance between cognitive ability and expertise?

By
Sabrina Stierwalt, PhD
3-minute read
Episode #238

My Ph.D. supervisor, a brilliant and inspiring man, used to jokingly tell me that he had passed his prime and that it was up to me to make the Nobel-prize winning discovery for our group. After all, Albert Einstein was just 26-years-old when he wrote his paper on Special Relativity.

But are we really at our smartest in our 20s? What about the wisdom and experience that come with age? At what age do we strike the right balance between cognitive ability and expertise? When does our intelligence peak?  

Fluid versus crystallized intelligence

It’s an inescapable fact that our cognitive abilities are destined to decline at some point. We will have a harder time remembering where we placed our keys or recalling the details of our favorite family story. However, our intelligence is, unsurprisingly, multi-faceted. We have fluid intelligence – that’s our ability to think quickly, solve new problems, and identify patterns – but we also have what psychologists call crystallized intelligence, which reflects our learned knowledge and ability to relate to our surroundings. These two forms of intelligence are thought to peak at different times in our lives.

In fact, in a recent study, published in the journal Psychological Science, researchers at Harvard and MIT found that even different aspects of fluid intelligence peak at different ages. Additionally, they found that there is not an age when even most of our brain’s abilities are at their peak.

The study, led by Joshua Hartshorne and Laura Germine and funded in part by the National Institutes of Health and the National Science Foundation, utilized a series of online cognitive games and tests available for anyone to try. This easy access dramatically increased the number of participants over a range of ages and thus formed the basis for the uniqueness of the new research. Historically, finding participants that are past college age but pre-retirement (in other words, roughly between 25 and 65 years of age) that are willing and able to participate in studies that require visits to laboratories for testing has proven challenging. The online study included roughly 3 million people over its first few years, including nearly 50,000 in each individual investigation. Hartshorne and Germine also compared their results to findings from much earlier, in-person studies and found those smaller studies supported their internet-based findings.

When does our intelligence peak?

Luckily for those of us who are no longer in our 20s, the results of the study showed that we don’t have to put ourselves out to pasture just yet. If you do not have access to the original article, the World Economic Forum has reposted some of the plots from the study for reference. For example, 50,000 test participants showed that our ability to to process information quickly peaks at around age 18 or 19. Our short-term memory tops out around the age of 25 and levels off for about a decade before it starts to slowly decline. Likewise, our skill at recognizing faces (along with many visual short-term memory tasks) is greatest when we are in our early 30s.

Our ability to assess other people’s emotions, however, doesn’t reach its peak until we are in our 40s or 50s.

Our ability to assess other people’s emotions, however, doesn’t reach its peak until we are in our 40s or 50s. Our overall knowledge, including vocabulary, and our big-picture comprehension, also don’t top out until we are around 50 years old on average. After that, they decline but just slightly before leveling off during our 60s (and eventually declining again in our mid-70s).

Why do our brains change as we age?

Researchers believe that changes in our brain’s structure may be linked to the changes observed in our cognitive abilities but more research is needed to fully understand the details of that possible connection. Just last week, researchers in the UK took a huge step in this direction by releasing a large dataset of newborn baby brain scans. This effort is being called groundbreaking and will allow a step-by-step look at human brain development at these crucial early stages.

The peak age for intellectual activity also appears to be shifting. For example, Nobel Prize winners are doing their award-winning work later and later, a result that is consistent across fields of study. The peak age for creativity in physics appears to be around 48 years old on average. So even if you still can’t find your keys, it may not be too late to write that novel or to tackle that next project when inspiration strikes.

Want to see how you stack up? You can check out the puzzles and brain teasers from Hartshorne and Germine’s study at www.gameswithwords.org and testmybrain.org.

Please note that archive episodes of this podcast may include references to Everyday Einstein. Rights of Albert Einstein are used with permission of The Hebrew University of Jerusalem. Represented exclusively by Greenlight.

About the Author

Sabrina Stierwalt, PhD

Dr Sabrina Stierwalt earned a Ph.D. in Astronomy & Astrophysics from Cornell University and is now a Professor of Physics at Occidental College.

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