Like every other part of the body, the brain starts to show the effects of age depressingly early. But that doesn't mean it's all downhill after high school. When it comes to cognitive ability and age, it's really a question of which types of intellect peak when. For some of them, the apex doesn't come until surprisingly far along.

Two new studies, which look at business-related cognitive skills, suggest that over our lifetimes, we reach the decline of certain abilities just as we're gaining ground in others.

For their study, Joshua Hartshorne of the Massachusetts Institute of Technology and Laura Germine of Massachusetts General Hospital looked at data from more than 48,000 participants. These individuals' cognitive abilities were assessed based on their performance on online exercises from gameswithwords.org and testmybrain.org, according to the Association of Psychological Science.

Here's what the research found:

  • Information processing speed peaks earliest, around age 18 or 19.
  • Short-term memory is strongest at about age 25, before it begins to drop around age 35. 
  • The ability to accurately identify others' emotions hits its peak during the 40s and 50s. 
  • Vocabulary skills reach their height in the 60s and early 70s.

Vocabulary skills were used as a measure of crystallized intelligence, or the ability to use acquired skills, knowledge, and experience. Another recent study also concluded that the older we get, the stronger crystallized intelligence grows.

Rachael M. Klein, a doctoral candidate at the University of Minnesota, studied 3,375 executive-level job candidates, ages 20 to 74. To measure fluid intelligence -- or logical reasoning -- she asked participants to do an activity involving sequences, and to measure crystallized intelligence, she asked participants to complete a vocabulary test.

Klein found that younger candidates out-scored their older counterparts on fluid intelligence quizzes. But older candidates once again dominated when it came to exercising crystallized intelligence skills.