What's Not To Like? Why Fondness Makes Us Poor Judges, But Dislike Is Spot-on

"The degree of false consensus depends on whether a person likes or dislikes an item," explain Andrew D. Gershoff (University of Michigan), Ashesh Mukherjee (McGill University), and Anirban Mukhopadhyay (University of Michigan).

Participants in one study were asked to choose a movie they like. They were then asked to guess what percentage of their peers liked the movie as well. On average, people estimated that 51.2 percent of other people also liked the movie, a significant overestimate. They also estimated that only 18.2 percent of people, on average, disliked it -- a reflection of the belief that more people agree with us than disagree.

In contrast, when asked to choose a movie they dislike and make the same estimate, participants were less self-centered: they thought people would agree and disagree with their opinion in roughly the same numbers.

As the researchers explain, "This finding arises from a deeper truth about the human mind, namely that things we like are seen to contain primarily good characteristics, while things we dislike are seen to contain a mix of bad, neutral, or good characteristics."

We might even like everything about an item -- except for one unforgivable, deal-breaking trait.

"This difference leads us to make more exaggerated predictions that people like the same things we do, compared to predictions that people will dislike the same things that we dislike," the researchers add.

Another study of ice cream sundaes found that those who liked a certain flavor combination -- say, mint ice cream with walnuts and hot fudge -- overestimated that people would share their fondness for the sundae by 9.9 percent. Those who disliked it only overestimated that people would share their repulsion by 0.8 percent.

They conclude: "Our research indicates that decision-makers in such situations need to be highly sensitive to the danger of over-projecting their own likes, more so than their own dislikes."

Andrew D. Gershoff, Ashesh Mukherjee, and Anirban Mukhopadhyay, "What's Not to Like" Preference Asymmetry in the False Consensus Effect." Journal of Consumer Research: June 2008.