Why do people spend decades tracing their lineages? Thinking about one's ancestors provides comfort, improves one's ability to deal with challenges and actually boosts cognitive performance, new research shows.

In a simple experiment, researchers asked people to think about their ancestors (or something else) and then measured their beliefs about their own performance on several cognitive tests. People who had been made to think about their ancestors expected to do better on the tests.

But did they actually do better? Yes. Researchers Peter Fischer, Anne Sauer, Claudia Vogrincic and Silke Weisweiler found that people who had recently thought about their ancestors actually did better on cognitive tests of intelligence than people who had been made to think of other things.

In a recent puzzle posted on The Hidden Brain's Facebook page, where all puzzles get posted first, I asked