Much of the research on how people make decisions has understandably focused on what people select when given an array of options. But, there has also been a strand of work that has focused on in choices. That is—how confident are people that the choice they made is a good one.

One big reason why confidence matters is that many decisions are made that precede actions that would need to be taken to actually implement the choice. A voter often has to decide on a candidate before going to the polls. A potential audience member has to be excited enough about a film to choose to go to the theater to see it. The greater people’s confidence that they have made a good choice, the more likely they will be to follow through on these actions.

A fascinating paper in the November 2017 issue of the Journal of Personality and Social Psychology by Hannah Perfecto, Jeff Galak, Joseph Simmons, and Leif Nelson looked at how the process by which the choice is made can affect confidence in the selection.

The proposed that people’s confidence increases when the process they use to make a choice is consistent with the options they are selecting from. In several studies, they gave people pairs of options that were either both good or both bad. For example, the items might be pairs of attractive faces or pairs of unattractive faces to be selected as possible models for an campaign or pairs of words naming positive concepts (joy vs. kiss) or negative concepts (murder vs. tumor).

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In some cases, people were asked to select the option they preferred. In other cases, people were asked to reject the option they did not want. When there are only two options, selecting or rejecting are functionally the same. If you select one option, you are (at least implicitly) rejecting the other).

After making a selection, participants rated their confidence in their choice. They also estimated the percentage of other people choosing who they thought would have made the same choice. This is a measure of consensus.

In each study, when the choice process was consistent with the type of option, confidence was higher, and people thought more other people would agree with them. That is, when people selected an option from among a pair of good options, their confidence (and belief in consensus) was higher than when they rejected an option from among a pair of good options. Similarly, when they rejected an option from a pair of bad options, their confidence (and belief in consensus) was higher than when they selected from among a pair of bad options.

Another study in this series also asked people to rate how easy it was to make a choice. Making a choice using a consistent process was easier than using an inconsistent choice. Differences in sense of ease of choosing predicted both confidence and belief in consensus.

A final study demonstrated a similar effect when the task involved selecting which of two items had more or fewer calories. Selecting the higher calorie item from a pair of high-calorie items (like a serving of ice cream or pepperoni pizza) led to more confidence and belief in consensus than selecting the lower calorie item from this set. Selecting the lower calorie item from a pair of low-calorie items (like rice cakes vs. celery) led to more confidence and greater belief in consensus than selecting the lower calorie item from a pair of high-calorie items.

These findings suggest that when a choice is easier to make, we are not only confident about it, but believe that other people will arrive at the same conclusion we did. This finding may be related to the observation that people also overestimate the number of other people who will vote for the same candidate they favor.