Let’s assume that most people don’t take as long as they think they will to decide if they like this blog. Of course, misunderstanding the speed of forming your opinions about blog posts is hardly an important mistake. However, if people systematically fail to anticipate how quickly they make judgments about a wide variety of topics beyond blog posts, this finding would take on more importance.

Our research suggests that this is the case. From evaluating artwork, novel foods, or goods and services to evaluating peers, political candidates, and marriage prospects, people use far less information than they think they will before making judgments and decisions.

(By the way, you have probably already made up your mind about this blog post by now.)

In one of our studies, for example, participants sampled a vegetable juice. We stripped all brand markings from the bottle so that people’s knowledge about the juice could not affect the findings (in reality it was V8 juice, Caribbean Greens flavor). Some participants (we dubbed them the “predictors”) were asked to predict how many sips they would need to take to decide whether they liked or disliked the juice.  Other participants (the “experiencers”) actually tasted successive sips of this juice until they formed their opinions about it. We found that predictors predicted that they would require about twice as many sips to decide as experiencers actually did.

We repeated this procedure in a variety of domains, including judgments of artwork, judgments of skill, and judgments of character, among others. In all cases, participants predicted they would view and use much more information than they actually did use to reach an opinion.

In another study—which led to a public self-reflection from Kathie Lee Gifford on the Today Show—we tested whether people fail to anticipate how quickly they make the decision of whom to marry. We asked people who had never been married to predict how long, after meeting their future spouse, it would take them to decide that this person was “the one.” Fully 39% predicted that this decision would take more than a year. We then asked married people to report how long deciding to marry their spouse actually took. Only 18% of married participants took more than a year to actually make this decision. Like our “predictors” in other studies, the never-marrieds overestimated how much time with their future partner they would need before deciding.

It’s important to make a distinction between how much information we actually use and how much information we think we use when making decisions. How much information we actually use depends on many factors, including the nature of the task. For example, we likely use more information to decide whom to marry than whom to befriend. But mistaken intuitions about how much information we think we use has importance consequences.

For example, this bias suggests that we may sometimes pay for information we end up not using. Paying for more information up front might also give us a false sense that we’ve covered all our bases, when in fact we do not use it to make decisions. For example, Consumer Reports now charges consumers a separate fee for their analysis of automobiles one car at a time. If a consumer pays for ten reports but buys the second vehicle he or she test drives, this is a waste of time and money. 

We might also misunderstand how quickly other people make up their minds about us. For example, one of our studies asked business students to write about their management experiences as part of an application for a hypothetical position. We then asked actual H.R. persons to evaluate these applications. Applicants wrote substantially more than the hiring professionals actually read, suggesting that the applicants over-worked to impress.

Finally, misunderstanding how quickly we make judgments can be especially detrimental when we have power over others. For example, managers might believe they will thoroughly assess their subordinates based on many observations when in reality they may make up their minds based on one (usually negative) instance. Such a quick assessment might be a catalyst for an insidious organizational malady—the self-fulfilling prophecy. Based on little evidence, a manager might evaluate an employee negatively and thus refrain from providing future opportunities to this employee, thereby “confirming” the initial negative evaluation.

Thanks to today’s technology, we have a wealth of information at our fingertips. Almost anything can be Googled or Wiki’ed. However, we may not realize how unlikely we are to utilize this abundance of information when making decisions.  So I’m guessing you liked this entire article about as much as you liked the opening paragraph. 


For Further Reading:

Klein, N., & O’Brien, E. (2018). People use less information than they think to make up their minds. Proceedings of the National Academy of Sciences, 115, 13222-13227. https://doi.org/10.1073/pnas.1805327115


Nadav Klein is an incoming Assistant Professor of Organizational Behavior at INSEAD.