For the past 20 years, some psychologists have made an appealing argument: that it's possible to achieve success or expertise in your craft by putting in lots of practice time. It's a nice idea: work hard enough and you have a shot at becoming, say, a great violinist. But this is an active debate among psychologists, and a new statistical analysis of 88 studies suggests that the exact opposite is true: that success mostly reflects other factors, like innate talent.

The new meta-analysis finds that practice only accounts for only about 12 percent of performance differences across all areas of expertise. For games like chess and scrabble, practice mattered the most (26 percent). In music, it was less important (21 percent). In sports, it accounted for 18 percent and in education, four percent.