“[Dr. Elizabeth] Spelke’s renown in psychology is based, in part, on her use of looking-time measures to answer questions not only about perception but also about cognition. Did infants have expectations of how the world worked—and could you tell what those expectations were by determining what surprised them? Spelke and several other researchers […] developed a provocative variation on the preferential-looking scheme, usually called the ‘violation of expectations’ study. These experiments were staged a little like magic shows. Babies sat in a darkened room, watching scenarios of varying degrees of plausibility unfold on a small stage. Spelke, for example, showed the babies a ball rolling along a path with an obstruction in the middle of it. A screen was lowered and then raised to reveal the ball either resting against the obstruction—where it logically should be—or on the other side of it, as though the ball had magically rolled through a solid surface. Spelke found that babies looked longer at the unexpected event.” The New Yorker’s Margaret Talbot on Harvard University’s Laboratory for Developmental Studies. See also this incredible image of the famous experiments.