Over at his blog, The Frontal Cortex, Jonah Lehrer has a post that references one of the most interesting and baffling studies on athletes ever performed. In 1985, Amos Taversky and Thomas Gilovich, two absolute giants in the field of cognitive psychology, looked at the shooting performance of the Philadelphia 76er’s, the Boston Celtics and the Cornell University men’s basketball team to see if what had happened over a player’s previous shots had any future, predictive effect on his next shot–are players on a shooting streak more likely to stay on that streak?
Here’s what they found:
Over 90% of basketball fans believe that a player has a better chance of making a shot after having made his last two or three shots, and 84% believed that it was important to get the ball to a player on a shooting streak. The professional basketball players themselves held similar beliefs about having a better chance to make a shot after previous makes, and also admitted to jacking up more shots than they normally would after hitting a series of consecutive shots.
Despite all of this, the researchers found no evidence for hot streaks beyond the random chance that a player with a given shooting percentage will sometimes hit some shots in a row. Players were no more likely to make a shot after having hit three in a row than they were after having missed three in a row, or in any other situation, either. The researchers used several different methods to try to find evidence of streakiness, including whether players had hot and cold games or mini hot and cold stretches within games. The result: nothing. Even Andrew Toney, who a survey of fans overwhelmingly included on their list of the five “streakiest” shooters in the league, showed no evidence of actually being a streaky shooter. The exact same findings were true for free throws, no streakiness existed.
These results run counter to our beliefs for several reasons. The first is that we humans are really terrible at detecting randomness, and we love to try to see patterns where none actually exist, especially when we can fabricate a story that tells us something that we want to hear. This is called confirmation bias, and it is one of the reasons that we will stick around at what we think is a hot blackjack table and dump money into a stock that’s been rising because we’re sure it will keep rising forever.
But the streaky shooter myth also disagrees with beliefs that most fans and athletes have about confidence and its role in successful performance, and these beliefs are supported by research. Free throw shooters that are more confident have been shown to be more successful, and it has also been demonstrated that artificially-induced anxiety and low confidence has the effect of decreasing shooting performance.
Another relevant psychological phenomenon is stereotype threat, which is the likelihood that a person will perform poorly on a test that they believe they are supposed to perform poorly on (see also: self-fulfilling prophecy). Stereotype threat was first observed in an experiment where African-American students at Stanford performed worse on a standardized academic test when they were told prior to the test that African-Americans tended to perform worse on that particular test. But stereotype threat has also been found to affect athletic performance as well. In a test of putting performance in golf, African-American golfers had their performance decrease when they were told that the test was meant to assess “sporting intelligence”. On the other hand, white golfers performed worse when they were told they were being tested for “innate athletic ability”. So there is a lot of evidence that what we believe about ourselves has a tremendous effect on our performance. It would seem to make sense that a player on a hot streak, one who believes that he’s about to hit all of his shots, should shoot better, but apparently they don’t.
The data from Taversky and Gilovich’s study is tough to argue with, and good studies are meant to kill our outdated, anecdotal beliefs about the world. But it also conflicts with a lot about what we know about confidence and its role in performance. While short hot and cold streaks may be, in fact, a myth, it would be interesting to see a study on what we might call “funks”, longer stretches when confidence is shaken and athletes’ beliefs in their ability break down. In these longer downswings an athlete might start to question his/her form and biomechanics and become overly self-conscious, something that has been demonstrated to hurt performance.
Either way, maybe you’ll watch basketball a little differently. And next time you’re playing maybe you’ll be more confident to take that open jumper after having missed a couple in a row, and more judicious with that fadeaway after knocking a few down.