"I rest my case."
Remarkably often in mock trials, here's what happens. Lawyers tell me they have an analogy or chart or argument they're sure will conclusively show their case is a slam-dunk win. They present this to the mock jurors, in a voice full of hard-earned pride. Then they listen to the jurors deliberate, and they're mortified. The jurors hate the analogy, trash the chart, use the argument to support the other side. The lawyer was so sure, and so wrong.
Good news from the world of social science: it's not just lawyers. Everybody does it. We all assume that if we like something, the rest of the world is going to like it too -- and when we assume that, we're usually mistaken. That's the conclusion of the wonderfully named paper "What’s Not to Like: Preference Asymmetry in the False Consensus Effect," by Andrew D. Gershoff, Ashesh Mukherjee, and Anirban Mukhopadhyay, in the coming June 2008 Journal of Consumer Research. A good press release is here.
With walnuts and hot fudge?!
The method used in the study was simple: ask people what they like and how much they think other people like it, and then ask those other people. So:
- "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."
- "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."
I can't help pointing out that a mock trial is essentially that same research method, minus the statistical precision. Lawyers bring in arguments they really like, and think other people will like them too. Then we ask those other people, and often they don't. Best of all, after the mock jurors are done chuckling at the argument, we listen to them talk about what did convince them, and we watch whether and how they're able to convince each other.
Where you're most certain you're right, then, is where you might be most wrong. A mock trial is one good way to find that spot, and set yourself straight.