We often think of the world as existing “out there” and that we simply open our eyes and see it for what it is. We also tend to believe that we observe other people’s reactions and pick out what is relevant based on what is actually there. Although this describes our experience of perception, the truth is actually quite different.

The facial scar experiment provides powerful evidence that people’s perceptions of social interactions arise from their expectations. The setup of the study, conducted by Kleck and Strenta¹, is as follows: Participants entering the study are informed that it is about how physical deformities impact interpersonal interactions. To explore this, participants have a significant facial scar placed on them and then are told to monitor the actions and attitudes of the others. A make-up artist puts the scar on the participants’ faces and has them look at it in the mirror. Then, she adds some moisturizer to help prevent cracking, and the participants have some brief social interactions. They later come back and report on those interactions.

Those with facial scars experienced the interactions as being much more tense and patronizing than controls. This makes sense, right? After all, we know people treat people with major disfigurements differently, right?

Well, it turns out that when the make-up artist added the moisturizer, she actually removed the scar. So, the person did not actually have anything on their face. Instead, they simply experienced the relational world differently because they had different expectations of what it would be like.

It is hard to emphasize how powerful this expectation effect is.

Consider, for example, the famous “gorilla experiment.” ² In it, individuals are asked to watch a group pass a basketball around and carefully count how many times the ball was passed for a minute. Unsurprisingly, most people can do this task relatively easily.

However, what is remarkable about this experiment is that while this is happening, a person in a gorilla suit enters the group, makes a display, and then walks off. When you see it, you can’t miss it. However, approximately 50 percent of the people who are counting the passes completely fail to see the gorilla. When you go back and take a look at the video, it is amazing that anyone would not notice the gorilla. But that is the power of expectations in forming what we see or, in this case, don’t see.

The work of the cognitive philosopher Andy Clark makes such phenomena understandable in his recent book, The Experience Machine: How Our Minds Predict and Shape Reality. The central idea in the book is called predictive processing, which is the theory that we build our perceptual experiences and act according to our predictions. One of the most compelling real-life examples he gives of predictive processing in action is of a construction worker who jumps off a large ridge only to land on a 10-inch nail and have it penetrate through his boot and stick out the other side. Needless to say, the man was in agony.

However, his perceptual experience changed dramatically when, after the boot was carefully removed, it became apparent that the nail happened to go between his toes and never actually pierced his skin. His agony was completely a function of his perceptions. If that sounds hard to believe, check out the rubber hand experiments³, which show how readily people can become convinced that a rubber hand actually is their hand, such that if it is crushed with a hammer, the person will jump back in pain.

The bottom line is that what you see is defined in large part by what you look for and expect to see. This is a powerful insight for many reasons. First, it highlights that our perceptual knowledge is always an interaction between the knower and what is known. Second, it helps explain how and why people can be at the exact same event but see it completely differently. Third, as this blog on the human identity matrix makes clear⁴, we have much flexibility in where we direct our attention and how we frame what we perceive and what it means to who we are. Thus, although the power of expectation can be a bit alarming and unsettling, it also can be very empowering, and it is one of the great insights of cognitive and narrative approaches to psychotherapy to realize how important our frame is in understanding how we experience and feel about the world around us.