When we say the words “science experiment”, it probably conjures up images of bubbling flasks of brightly colored chemicals, or shooting laser beams, or basically anything from the opening sequence of Dexter’s Laboratory. It probably doesn’t make you think of a bunch of people sitting in a room watching a video of someone shaking a box. But scientists recently carried out this last experiment, and behind a deceptively unglamorous exterior is a fascinating insight into the workings of the human brain.

This experiment aimed to test something that you are likely very skilled at, even if you’ve never thought about it before. Come for the science, stay for the ego boost.

“Just by looking at how someone’s body is moving, you can tell what they are trying to learn about their environment,” explained study author Chaz Firestone, an assistant professor at Johns Hopkins University, in a statement. “We do this all the time, but there has been very little research on it.”

What Firestone is referring to here is a type of behavior called an epistemic action. These are actions we perform when we’re trying to learn some information about an object or our environment. What the box-shaking experiment demonstrates is that humans are very good at understanding the reasoning behind someone else’s behaviors.  

The team recruited 500 people and asked them to watch these two videos of someone shaking a box.

Could you tell who was trying to figure out the number of items in the box, and who was trying to figure out the shape of the items? Almost all of the 500 participants could, and they figured it out within seconds.

“What is surprising to me is how intuitive this is,” said lead author Sholei Croom. “People really can suss out what others are trying to figure out, which shows how we can make these judgments even though what we’re looking at is very noisy and changes from person to person.”

The next thing the team would like to investigate is how adept we are at telling the difference between epistemic actions and another, sometimes similar, class of behaviors called pragmatic actions. 

For example, you might dip your toe into the bath to check the water temperature before diving right in – that would be an epistemic action. However, you would also probably place your foot in the water first if you were simply getting into the bath, secure in the knowledge that the water was just right – that would be a pragmatic action.

“It’s one thing to know where someone is headed or what product they are reaching for. But it’s another thing to infer whether someone is lost or what kind of information they are seeking,” Firestone summarized.

Far from simply being a fascinating window into an under-studied area of human cognition, this work could have real-world implications. One example is in the field of artificial intelligence (AI), developing robots that can deduce what we’re looking for from our actions, just as we humans do all the time without realizing.

The team, which also included sophomore neuroscience student Hanbei Zhou, is also keen to learn more about when in human development these undeniably impressive skills start to appear.

Firestone said, “When you think about all the mental calculations someone must make to understand what someone else is trying to learn, it’s a remarkably complicated process. But our findings show it’s something people do easily.”

Go us!

The study is published in the Proceedings of the National Academy of Sciences.