But psychologists have identified two types of intelligence that flourish at different stages of life.

 But psychologists have identified two types of intelligence that flourish at different stages of life. 

The first is fluid intelligence, which helps young adults innovate and solve novel problems and typically peaks in our late 30s.

 The second is crystallized intelligence, which enables older adults to use the knowledge they’ve acquired in the past to identify patterns and educate others about the intricacies of complex ideas and systems.

 And it’s important to understand the difference because people who assume that it’s curtains for their career once their fluid intelligence wanes may actually behave in ways that hurt their performance and health. Indeed, controlled clinical studies of so-called negative self-stereotyping have shown that when older adults are presented with negative age stereotypes and apply them to themselves, they perform more poorly on memory tests and even walk more slowly.