There are times when I’m deep in conversation with a good friend, talking through why she or I made some decision: why we took the job, dated the guy, moved to a new apartment, whatever. And sometimes, all of a sudden, it’s like all the dots connect: Oh, that’s why I did that. It feels like a flash of introspective insight. But … is it, necessarily? Or did I maybe just come up with a rational explanation for an objectively weird decision?
Carl Jung once said that “in each of us there is another whom we do not know.” A shorter, more modern version of that might be the “introspection illusion,” a term coined by Princeton psychologist Emily Pronin to describe the cognitive bias that essentially makes the same point as Jung: You don’t always know your own thoughts and feelings as well as you think you do.
You are, of course, aware at any given time what you are thinking or feeling. You know if you are angry or hungry or sad or happy, and you know when you are thinking about your weekend plans when you should be concentrating in a meeting. But if I were to ask you why you were thinking or feeling the way you are currently thinking or feeling — things get complicated: The evidence suggests there’s a good chance your answer would be at least kind of made up.
This tends to show up in the way people make decisions — or, more specifically, in the way people explain their decisions after they’ve made them. In a weird experiment that illustrates this concept, researchers showed people two photographs, each one of a different person. The study volunteers were to study the photos, and select the person he or she found more attractive. Simple enough so far. Next, the experimenter took the photos back, and then surreptitiously switched them around, and put one of them facedown in front of the study volunteer. The volunteer then flipped the photo right side up, and was instructed to look at it again and explain their choice. Why is this person more attractive than the other?
The catch, as you might’ve guessed, was this: Some people were given the wrong photo. Some of the study volunteers were handed the picture of the person they’d deemed less attractive, while others were indeed handed back the picture of the person they’d found more attractive. Some people noticed the switch, but not as many as you might expect: Only about a quarter caught on.
But here’s where it gets interesting, as University of Chicago psychologist Nicholas Epley explains in his book, Mindwise:
[W]hen asked to explain their choice, there was no difference in the reports given by those who were explaining the photo they’d actually chosen as being more attractive and those given the one they had not actually chosen. People who were shown the card they had not chosen nevertheless told a completely compelling story explaining why they had chosen that photograph. They failed to notice the card switch and so they devised a perfectly good explanation for a choice they had not actually made.
People in both groups tended to make up a little story, in other words, one that rationalized their decision. Other studies have come to similar conclusions. In one, researchers asked people at a shopping mall to choose between “four identical pairs of nylon stockings,” and to then explain their choice. Again, all the stockings were the same — but that didn’t stop many of the participants from coming up with stories about why they’d chosen this pair over the rest. Studies like these helped change the way social psychologists conduct their experiments in the first place. In the early days of modern social psychology, many researchers behaved a little bit like overgrown toddlers, in that they tended to ask their study volunteers one question over and over: Why? Why do you like this politician more than that one? Why did you take your current job? Why did you marry him? Why did you move house, or change therapists, or go to grad school, or fail to use contraception? Why? Why? Why?!
These days, psychology researchers have moved on to observing people’s behavior in their relentless pursuit of trying to understand why people do the things they do. In the stockings example, for instance, what seemed to matter most was the order in which people evaluated their choices; they picked the last option four times more often than they picked the first one. Not one of the study subjects realized the order might have influenced their decision. “And when asked directly about a possible effect of the position of the [stockings],” the study authors elaborate, “virtually all subjects denied it, usually with a worried glance at the interviewer suggesting that they felt either that they had misunderstood the question or were dealing with a madman.”
One of the authors of that study, Timothy D. Wilson, went on to write a book with a title that echoes the “introspection illusion” idea: Strangers to Ourselves. In it, he argues that although it is indeed a worthwhile pursuit to “know thyself,” you’d do better to pay more attention to what you do than how you feel or what you think — this, after all, is what your friends are doing, and there is evidence to suggest that they are often more accurate judges of your personality than you are. As the oft-Pinned and Instagrammed quote says: Don’t believe everything you think.