When you see a ball rolling toward a wall, you know it will stop when it reaches the solid surface. This isn't something you learned, it's something you just know — even as an infant. It's called core knowledge, and a new study shows that babies are not only born with core knowledge, but they learn best when its rules are broken.

Let's go back to that rolling ball for a second. Researchers from Johns Hopkins University set up an experiment in which 11-month-old babies sat in a high chair and were shown "magic" tricks, like a ball that rolled "through" a wall.

ball rolls through a wall; magic tricks for babies

Or a truck that seemed to "float" in the air. 

truck floats in the air; magic tricks for babies

As the ball rolled through the wall or the truck floated over the surface, the babies were genuinely shocked.  

"Some pieces of knowledge are so fundamental in guiding regular, everyday interactions with the environment, navigating through space, reaching out and picking up an object, avoiding an oncoming object — those things are so fundamental to survival that they're really selected for by evolution," Lisa Feigenson, a professor of psychological and brain sciences at Johns Hopkins and a lead researcher for the study, said in an interview with NPR

What's more, researchers found that by surprising the babies with tricks that broke the rules of their core knowledge, it sparked the babies' interest in learning.

After the experiment, when the babies were offered toys to play with, they immediately selected either the ball or the truck, and researchers found that they played with these toys in ways that suggested they were trying to better understand how they broke the rules of physics.

baby plays with ball after Johns Hopkins experiment

When babies were shown a ball that stopped at the wall, they didn't give it a second glance after the experiment. But when they saw what looked like the ball going through the wall, they played with it and repeatedly banged it on the tray of the high chair — as if trying to test it.

Same thing with the truck; babies who saw what they thought was a truck floating in the air immediately selected the truck to play with after the experiment and tested it by rolling it off of the high chair.

The babies also retained more information about toys that surprised them. For instance, when they were shown that the ball also squeaked, they remembered that more easily than they did information about the other toys they were given. 

So what does all this mean? It means that babies are very sophisticated learner, and they learn best when something surprises them. 

"Our research suggests that infants use what they already know about the world to form predictions," said Feigenson. "When these predictions are shown to be wrong, infants use this as a special opportunity for learning."

It's a good thing that life is so full of surprises.

Photos: Courtesy of Johns Hopkins University

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