We base our everyday behavior on thousands of predictions about how reality will unfold around us as we interact with our physical and social environment. Some of our expectations are the product of hard-won experience and direct interaction with the world. Other expectations are programmed in infancy, and hard-wired into our neural systems with little or no exposure to external stimulation. Scientists refer to the latter set of expectations as “core knowledge”. Some examples of it are our understanding that solids will not go through walls, or that objects will fall if dropped.
Magic acts hinge on defying all sorts of expectations about the way things should be. Confronted with the violation of their core predictions, audiences become captivated. The most jaded spectator can feel a kind of childlike wonder in front of a talented magician. A new research study investigating how babies react to violations of their prior expectations may explain why magic is so compelling to audiences of all ages.
Aimee E. Stahl and Lisa Feigenson from Johns Hopkins University thought that violations of one’s expectations about the world might signal special opportunities for learning. Previous research had shown that babies stare for longer times when their expectations are violated; for instance, if a ball appears to pass through a wall rather than being stopped by the wall, or when an actor approaches someone mean rather than someone nice. It was not known however, whether the babies’ increased interest in entities that didn’t behave as they should had any cognitive utility.
The scientists hypothesized that violations of expectations might provide opportunities to learn about the world. If so, infants should preferentially learn new information about objects that violate expectations, seek information about those objects, and explore the objects in such a way as to test possible explanations for their bizarre behavior.
The researchers tested one hundred and ten 11-month old infants in an elegant series of experiments. First, the babies watched as toy cars or balls went through walls or were stopped by them (among other physically possible and impossible scenarios). Then, the scientists showed the babies something new about the object they had just observed: for instance, that it squeaked when pushed. The babies learned to associate the sound with the object only if the object had violated their expectations previously. This meant that learning was not generally enhanced following a violation-scenario, but was restricted to the specific objects that violated the babies’ expectations.
Next, the scientists had the babies watch events that were either congruent with, or in violation of, basic principles such as object solidity (the object appeared to pass through walls) and object support (the object appeared to hover unsupported in midair). Then, the infants had the opportunity to explore and play with the object they had just watched (the target object) and also with a new object (distractor object). The babies spent more time exploring the target object if it had previously violated core principles. When the object behaved consistently with their expectations, babies played equally with the target and distractor objects. Even more fascinating, the children interacted with target objects that had violated expectations in ways that critically depended on the type of violation observed. The babies who had seen the object go through a wall banged it repeatedly against the table, as if testing its consistency, whereas the babies that had seen the object float in the air dropped it over and over again. That is, the kids tailored their explorations to the type of violation witnessed. This dissociation indicates that the babies were not just reacting in random ways to the surprising scenarios, but were systematically testing their environments, much as scientists do when puzzled by an unpredicted piece of data.
But what about adults confronting the unexpected?
As adults, we don’t often experience radical violations of our expectations, particularly those that concern core principles of object behavior. One important exception is magic -- A magic performance turns our reasonable expectations upside down: objects vanish, levitate and metamorphose. What if each of these violations signals a unique learning opportunity not only to the infant brain but to the adult brain as well? It may be that magic performances are so compelling because we are wired to engage our minds and actions in unexpected situations.
At the Magic of Consciousness Symposium that Stephen Macknik and I co-hosted in 2007 in Las Vegas, Teller, the mute half of the magician duo Penn and Teller, eloquently proposed that much of our lives is devoted to understanding cause and effect, and that magic “provides a playground for those rational skills”. A baby’s playground is as large as the world, filled with everyday wonder and opportunity. As we age and learn, the amazement and playfulness shrinks -- but we can always rely on magic for a visitor’s pass to the stunning playground of the mind.