Recommendations You Hear Are Particularly Persuasive

iStock image by Alvarez licensed to Art Markman

These days, almost everyone has some kind of smart speaker at home that will play music or the radio, control aspects of the house, and even make recommendations for things to buy or watch. These devices add to the dizzying array of technology that tries to guide our choices.

Of course, you’re probably used to being surrounded by recommendations. If you shop on any website, it recommends additional products. TV shows and newspapers are loaded with reviews of products as well. And, of course, your friends often tell you about things they have tried and liked (or hated). That means that you’re seeing a lot of recommendations, but also hearing them.

Does it matter whether you hear a recommendation or see it?

This question was explored in a paper in the January, 2023 issue of Psychological Science by Shwetha Mariadassou, Christopher Bechler, and Jonathan Levav.

They ran a series of studies involving a similar design in which they had people make decisions about a set of items. In some cases, the choices were part of a fictional vignette (imagine you had to choose a beer to go with a ramen dinner). In some cases, the choices would affect subsequent actions of the participant (later in this study, you will have to do one of two tasks). Then, participants were given a recommendation that was supposed to have come from another person. For some participants, the recommendation was written down. For other participants, it was spoken. Then, participants selected an option.

Across all the studies, participants were consistently more likely to select an option that was recommended if they heard the recommendation than if they saw it. The studies used different kinds of voices (like human actors speaking the recommendations or a computer voice, like those used by smart speakers).

Why does this happen?

The studies suggest that hearing a recommendation creates a greater sense of urgency, because the recommendation is only available when it is spoken, while people feel that they can go back and look at written recommendations at any time. There are several converging sources of evidence that this sense of urgency matters.

In one study, the written recommendations were only available for a brief period, just as the things you hear are gone as soon as they are spoken. In this case, participants were also more likely to select the recommended item than they were when the written recommendation remained available. In another study, participants were asked to rate whether they felt urgency to make a choice. They felt more urgency when hearing a recommendation than when reading it, and statistical tests suggest that helps explain some of the difference in people’s likelihood of selecting the recommended item. Finally, looking across all studies, participants made their choices more quickly in the condition in which they heard the recommendations than when they read the recommendation suggesting they were actually feeling this greater sense of urgency.

The idea is that when you act quickly, you are not deliberating about the decision, and so you are likely to go with easily available sources of information, like a recommendation, rather than thinking through your own preferences or integrating multiple sources of information to make a choice. These findings suggest that if you are in a situation in which you hear recommendations, it might be valuable to write out the recommendation and take your time to decide.