Why do some people, chess players or musicians, practice less but attain more?

The common belief is that practice is necessary to achieve mastery in chess, but it's not enough. There has to be something else that sets apart people who get really good at chess, just like in music. A study published in Psychological Science last year found that musicians need a lot of practice, but researchers identified one additional factor: musicians who are better at sight-reading have better working memory, the ability to keep relevant pieces of information active in your mind.

For chess, that additional factor has not yet been pinned down. One possibility is intelligence. A lot of studies have found that children who play chess have a higher IQ than the general population but studies have found mixed results on whether adults who play chess have higher IQs than adults who don't play chess. And only one study—of several that have been performed—found that adults with higher IQs are better at chess.

Guillermo Campitelli of Edith Cowan University in Australia and Fernand Gobet of Brunel University in the United Kingdom suggest that more intelligent children may be attracted to chess, and use their good reasoning skills to play well, but later they need to practice hard to learn all the strategies and plans that make a good chess player—and intelligence isn't much help.

Other things that set apart chess players are handedness—while about 90 percent of the general population is right-handed, only about 82 percent of adult chess players are right-handed. This could indicate some difference in brain development that makes people better at the spatial skills you need to be good at chess. But it still doesn't explain what makes some people better at chess than others.