Psychologist Richard Gregory conducted something called The Hollow Face Experiment because he believed that our visual perception relies on something called top-down processing.

Top-down processing, also known as conceptual-driven processing, happens when we form our perceptions beginning with the big picture.

In short, we utilize expectations, beliefs, prior knowledge, and past experiences to make a best guess as to what we see.

In other words, when we see something all we’re really doing is making calculated assumptions.

Here’s how his experiment worked.

He used the rotation of a Charlie Chaplin mask to explain how we perceive the hollow surface of the mask as protruding based on our expectation of the world. Our prior knowledge of a normal face is that the nose protrudes. So, we subconsciously reconstruct the hollow face into a normal face.

Based on Gregory’s theories, we can say that:

So what does this experiment prove?

It proves that we all see things differently.

Even things as objective as an apple can be perceived slightly differently among a group of people so you can imagine how differently we perceive more subjective things like thoughts, onions and behaviors.

The most effective way to bridge the gap between the way that you see the world and the way your subject sees the world is through rapport.