Everything looks bigger when you’re a virtual child

If you’ve gone back to your old elementary school recently, you’ll recognize the feeling: classrooms, desks, and playgrounds that you used to think were huge and expansive are suddenly tiny, unimpressive, and claustrophobic. We perceive the world around us very differently as adults compared to back when we were kids. But can we return to that earlier state, seeing objects and places as we did when we were little?

By experimenting with virtual reality avatars, a group of European researchers found that seeing the world through someone else’s eyes is possible—and it can change how we think. By tricking subjects’ brains into thinking they were inhabiting the body of a child, the scientists could actually alter how people perceived objects in their environment.

Several earlier studies have suggested that virtual reality can let a person “own” a body that isn’t theirs; for instance, people experience physiological changes such as heart rate deceleration in response to a threat to their avatar in a virtual world, just as they would in real life. However, whether or not this “ownership” extends to the way that a person perceives the surrounding environment hadn’t yet been explored.

To test this idea, the researchers recruited 30 adults and fitted them with a head mounted display and a body-tracking suit. The participants then entered a virtual world as either a four-year-old child or as an adult (sex-matched to each participant’s gender). The two avatars were exactly the same height (a virtual 91.5cm), so all participants experienced the scene from the same eye level; the only difference was how mature their bodies looked. The participants explored the virtual world from a first-person perspective but could look into a mirror in the simulation to see what their virtual body looked like. In this phase of the experiment, their avatar moved synchronously with them in order to encourage a feeling of body “ownership.”

While exploring the simulated environment around them, the subjects came across three cubes of different sizes (15cm, 30cm, and 45cm, respectively). They were asked to estimate, using the distance between their outstretched hands, how large each of these boxes were; sensors placed on their hands measured and logged each estimate.

When the researchers analyzed the data, they found that all the participants tended to overestimate the size of the boxes. However, while inhabiting the toddler’s body, people overestimated the box size by a much greater extent—about twice as much—as they did in while inhabiting the adult’s. The results were unambiguous: experiencing the world through a child’s body makes things seem much bigger.

Since both avatars were equally tall, it wasn’t height or eye level that influenced how participants perceived the objects in the virtual room. Even the child and adult avatars’ clothes were the same; only their body proportions differed. Something about merely seeing the body of a child—and feeling as if we are inhabiting it—can actually help us experience the world as we did when we were young.

But the sense of actually being the avatar is integral to the response, it turns out. The researchers ran another trial that was identical to the first, except for the fact that the avatars did not move synchronously with the participants. In these trials, the participants reported much less intense feelings of “ownership” over their virtual bodies, and there were no discernible differences in the size estimates of the boxes between those with child and adult avatars. Altering a person’s perception via virtual reality therefore depends on a strong feeling of actually inhabiting the avatar’s body.