The False Consensus Effect

03.11.2018 |

Episode #10 of the course Most brilliant social psychology experiments by John Robin


Welcome to the last stop on our tour of popular social psychology experiments.

Today, we are going to explore another cognitive bias that is just as powerful and widespread as the halo effect we discussed yesterday.

This one is known as the false consensus effect, and it relates to our tendency to overestimate how much other people agree with us.


How We Deal with Conflict, Especially How We Avoid It

In 1977, Stanford University social psychologist Lee Ross set out to understand more about biases in human decision making, particularly when it comes to misunderstanding others’ behavior. He was especially interested in when this causes problems during peace talks and dispute resolution.

To understand this, he conducted two experiments.

In the first experiment, the participants were told about a specific conflict, then they were told that there were two ways to resolve it. They were given three tasks:

• First, take a guess at which option they expected others to choose.

• Second, state which option they would choose.

• Last, describe what kind of person would choose either option.

The results were quite staggering:

Most people, regardless of which option they chose, expected others to choose similar to them, and when describing the kind of people who would choose the opposite, they described their personalities with extreme language. Collecting the results, Ross generalized these descriptions by concluding most subjects described those who chose differently as being abnormal.

The powerful implication: We assume those who don’t agree with us have something wrong with them.

The second experiment only further reinforced this trend:

Subjects were asked to take a walk around the Stanford campus for 30 minutes wearing a sandwich board. “Eat at Joe’s,” it said. However, “Joe’s” didn’t exist, and the students were not given any information about it. They were essentially being asked to walk around for 30 minutes and look stupid—or were they? (See the results …)

They were all told that if they did this, they would learn something interesting afterward. They were also given the option to not do it.

The subjects were also asked in this experiment what they thought other participants would choose.

As with the first experiment, there was a high tendency to think most chose the same as them, while those who didn’t were described as dumb or crazy or other extreme variations of this.

• Among those who agreed to wear the sandwich board, 62% thought others would agree to wear it too.

• Among those who refused, 33% thought others would wear the sandwich board.

Though everyone had unique answers, they reflected similar logic:

• For those who agreed to wear the board, they criticized those who refused as being afraid to look stupid.

• For those who refused, they called the ones who chose to wear the board as show-offs.


The Consensus (Not the False One)

These studies and future studies inspired by it have led psychologists to understand something about psychology itself: We are really bad at guessing what we expect people to do. This is why psychologists design experiments that challenge assumptions.

You can apply this to our whole course so far, which is why I saved this for the end.

You’ve seen ten fascinating experiments that show you different things about how people actually behave. If these experiments seems “strange” to you at first, then you’re under the false consensus effect:

• You find yourself either saying, “That’s obvious, I could have told you that!” because you identify with the concept and assume those who don’t must be missing something.

• Or, you find yourself saying, “No, that’s not my experience. People don’t behave that way,” because you don’t identify with the concept and assume anyone who does must be weird.

So, there you have it. Ten social psychology experiments that will change how you think. But remember as you leave this course: What you assume to be common sense might not be the truth shared by everyone you know.

I hope you learned a lot. Please share this course with all your friends so they can be enlightened and like you, begin breaking free of the false consensus of assumptions we live under—you’re on the right path by doing things like taking great Highbrow courses and all the other things you do to learn a little something every day!


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Other courses by John Robin

How to market your book online

How to begin (and maintain) your career as a writer

Great math problems for the 21st-century mind

Foundations of mathematics

The world’s most compelling logic puzzles

Brain-twisting paradoxes


Recommended book

Continue to learn about the power of social psychology in this hallmark book, Influence by Robert B. Cialdini.


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