Different aspects of fluid intelligence — the ability to analyze information, engage in critical thinking, and solve problems — peak at different ages, and some may peak as late as age 40, according to a new study published in the journal Psychological Science, a journal of the Association for Psychological Science.
“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,” said researcher Dr. Joshua Hartshorne, a postdoctoral researcher at the Massachusetts Institute of Technology and one of the paper’s authors.
The researchers ran a large-scale study by using the websites gameswithwords.org and testmybrain.org. They examined four different cognitive tasks, as well as a task that measured participants’ ability to perceive others’ emotional state.
The findings from nearly 50,000 participants of a variety of ages provided a very clear picture showing that each cognitive skill peaks at a different age.
For example, the speed with which participants processed information appeared to peak early, around age 18 or 19, and then immediately started to decline. Short-term memory seemed to improve until around age 25, level off for several years, and then begin to drop around age 35.
“It paints a different picture of the way we change over the lifespan than psychology and neuroscience have traditionally painted,” said study co-author Dr. Laura Germine, a researcher in psychiatric and neurodevelopmental genetics at Massachusetts General Hospital.
The ability to evaluate other people’s emotional states, however, peaked at a later age, when participants were in their 40s or 50s. Although researchers aren’t sure why these skills tend to peak at different ages, prior research suggests that it may have to do with changes in gene expression or brain structure as we get older.
The study also included a vocabulary test, which serves as a measure of what is known as crystallized intelligence — the accumulation of facts and knowledge. While the findings confirmed that crystallized intelligence peaks later in life, the new data indicated that it peaks in a person’s late 60s or early 70s, even later than previously thought.
The researchers believe this could be explained by today’s adults having higher levels of education, jobs that require a lot of reading, and more opportunities for intellectual stimulation in comparison to previous generations.
The researchers continue to gather data and have now added cognitive tasks designed to evaluate social and emotional intelligence, language skills, and executive function to the suite of tests included on their websites. They also plan on making their data available to the public so that other researchers can have access to it and perform other types of studies and analyses.