Is there such a thing as too much feedback?

The world is a complicated place. Reality is dense with patterns, but these patterns are often subtle and inconsistent. We think we understand how things work – X always causes Y – but then Z happens. It’s very confusing.

Needless to say, such complexity poses a big problem for biology. How should animals learn from such unpredictable situations? What’s the best way to cope with contingency?

…To answer these questions, Tal Neiman and Yonatan Loewenstein at the Hebrew University of Jerusalem turned to professional basketball. More specifically, they looked at 200,000 three-point shots taken by 291 leading players in the NBA between 2007 and 2009. (They also looked at 15,000 attempted shots by 41 leading players in the WNBA during the 2008 and 2009 regular seasons.) The scientists were particularly interested in how makes and misses influenced subsequent behavior. After all, by the time players arrives in the NBA, they’ve executed hundreds of thousands of shots and played in countless games. Perhaps all that experience reduces the impact of reinforcement, making athletes less vulnerable to the unpredictable bounces of the ball. A make doesn’t make them too excited and a miss isn’t too discouraging.

But that’s not what the scientists found. Instead, they discovered that professional athletes were exquisitely sensitive to reinforcement, so that a successful three-pointer made players far significantly more likely to attempt another distant shot. In fact, after a player made three three-point shots in a row – they were now “in the zone” – they were nearly 20 percent more likely to take another three point shot. Their past success – the positive reinforcement of the made basket – altered the way they played the game.

In many situations, such reinforcement learning is an essential strategy, allowing people to optimize behavior to fit a constantly changing situation. However, the Israeli scientists discovered that it was a terrible approach in basketball, as learning and performance are “anticorrelated.” In other words, players who have just made a three-point shot are much more likely to take another one, but much less likely to make it.

…Although people can’t help but learn from the reinforcement signals of the world – that’s just the way the mind is designed – we need to remember that these signals come with stark limitations, especially when they emerge from a complex situation. Sometimes, the best thing we can do is not learn from what just happened.

Continue reading

Jonah Lehrer is the author of How We Decide and Proust Was a Neuroscientist.