It's not all downhill once you hit your 20s - at least as far as some markers of intelligence are concerned.
Not only do we get wiser with age, new research suggests that in several ways we may also actually get smarter.
As expected, the research found that some skills, like our ability to think quickly and recall information (also known as fluid intelligence), follow the familiar pattern: peaking around 18 and falling over the course of the rest of our lives.
But our other abilities, from reading others' emotions and recalling events that have just happened, continue to improve until we turn 30. And other skills, including our ability to do basic math (black line) and use a larger vocabulary (yellow line), rise even later, in most cases not reaching their apex until age 50:
STM = short-term memory; WM = working memory; WAIS = Wechsler Adult Intelligence Scale
The researchers got their results by widening the net of people they studied and looking specifically at how age affected peoples' results on different types of tests, rather than simply lumping similar tests together and looking at their overall results.
In addition to looking at how people did on a commonly-used Wechsler intelligence test, the researchers included their results on other cognitive tests that they made available online, including a vocabulary and face-recognition quiz.
This gave them access to a huge database of information from people of all ages: Overall, the study included the test results of 48,537 people between age 10 and 89, with about 10,000 people participating in each test.
One important caveat of this approach is that because it didn't didn't follow the same people over the course of their lives, the results could overlook differences based on socioeconomic status, culture, or generation.
Still, the results are striking, and they appear to square with other recent studies challenging the idea that we reach peak intelligence in early adulthood.
A 2011 study looking at data from more than 60,000 people, for example, found that our ability to recognize faces continues to improve as we age - until just after we hit age 30. Those face-recognition tests were one of the components of this study.
"At almost any given age, most of us are getting better at some things and worse at others," lead study author and MIT department of brain and cognitive sciences researcher Joshua Hartshorne told Business Insider.
"There may not be an age where you're the best at everything," said Hartshorne.