University of Southern California

When The Blind Lead The Blind
October 22, 2010

We can't escape opinion polls. They're everywhere—telling us how everyone feels about everything. But when do they stop reflecting what other people think and start influencing how we think?

To study this issue, USC’s Mat McCubbins and co-author Cheryl Boudreau (UC Davis) wanted to know who is affected by polls and how polls affect citizen’s decision making. Their Journal of Politics article looked at the decisions of people who made decisions on their own, and compared them to the decisions of different groups who received polling results before they made their decisions.

The authors found that people were more likely to want to look at polls when they faced a tough decision and when they were unsophisticated voters. The reason why this is worrisome is that the unsophisticated typically don’t have the knowledge that allows them to judge whether polls are accurate or not. Hence, they can fall victim to the potentially biased recommenders. Interestingly, decision makers were just as likely to want to receive polls from pollees that were credible as those that lacked credibility. These results suggest that people pay more attention to what people say than with whether they are credible sources of information.

An interesting outcome was that people paid more attention to the direction of the outcome (i.e., which option won out) than to how big the gap was between the options (how much the option won out by). Logically, it’s the size of the gap, not the direction that should hold more sway. These effects hold both when decisions makers freely choose polls as well as when they are forced to see them.

The bottom line: People are more likely to look at polls when they polls are least likely to help them (when the decisions are complex and the they are themselves unsophisticated). They are not good at distinguishing between credible and non-credible polls and they don’t pay attention to the size of the gap between the options—only the direction. In sum, people put tremendous faith in what the majority thinks, even if the majority’s views are wrong and/or biased.

To learn more about Mat McCubbins and his work on politics and communication, visit his webpage here.