After learning to solve a problem one way, we're blind to more efficient methods. Research reveals why: Even when we think we're surveying new conceptual terrain, our attention is still locked onto familiar features.
Experienced chess players asked to find the shortest path to checkmate all spotted a common five-move strategy, then kept looking for something better. Yet they all missed a less-common three-move maneuver. (Equally talented players found the short win when it was the only one available.) Eye-tracking data revealed that their gazes failed to stray from the squares relevant to the first solution.
One might conclude that expertise put them in a rut and that fresh eyes could have yielded more insight, but in a companion study flexibility increased with experience, with stronger players more likely to find the shorter solution. "It's kind of counterintuitive," says Merim Bilalic of Tuebingen University in Germany. Having a little knowledge got them into a groove, but having a lot got them back out.