Source: Dan McCoy CC0 via Wikimedia Commons

When you see other people in the world, there are several predictions you often make about them. You often want to predict what they will do (like whether someone standing at a crosswalk is about to head out into the street in front of your car). You also want to predict why they do what they do. For example, that person might be walking into traffic, because they are in a hurry or because they are generally impulsive.

The pioneering work of the Harold Kelley suggested that people are trying to figure out the causes of other people’s behavior. In some situations, there is nothing to figure out. When people engage in behaviors that everyone does, then we can just appeal to a social norm to explain behavior. For example, there is no need to explain why a particular person stands facing the door of an elevator.

When someone engages in a behavior that is not typical, though, then there is something to be explained. If you see a man yelling at the cashier at a store, then that is an unexpected behavior that you want to explain. You might think there is something specific about the situation that caused the behavior. Perhaps the cashier made a costly mistake that angered the customer. Another explanation is that the customer had a goal he was trying to accomplish like to be aggressive in order to get a refund that was different than store policy. A third possibility is that the person has a trait that led to the behavior. This man just might be mean.

How do people determine which of these explanations to give?

A lot of work on the suggests that people explain their own behavior based on situations, but other people’s behavior based on some characteristic of that person. Still, though, that doesn’t determine whether that characteristic is a goal (like trying to get a refund) or a trait (like being mean).

A paper in the February 2018 issue of the Journal of Personality and Social Psychology by Irmak Okten and Gordon Moskowitz examined this question.

They argue that when people have an atypical behavior they want to explain, there are two dimensions they take into account in figuring out what kind of explanation to give. They are focused on whether the person does the behavior all the time or just once (consistency) and whether they do it only in particular circumstances or everywhere (distinctiveness).

They argue that behaviors that are highly consistent (they are done all the time) and not particularly distinctive (they are done in all situations) lead people to explain the behavior with a trait. Behaviors that are either not that consistent (they are not done that often) or are quite distinctive (they are done only in specific situations) lead people to explain the behavior with a goal, because are often specific to particular contexts.

Across several studies, participants read about the behaviors of a person. For example, someone might clip coupons. That is not a behavior everyone does, so it needs some explanation. Studies varied either the consistency of the behavior, the distinctiveness of it, or both. As a manipulation of consistency, the person might always clip coupons, or they might only clip them one time. As a manipulation of distinctiveness, the person might gather coupons only from the newspaper or from newspapers, magazines and on-line sources.

In some studies, participants made ratings of how much that behavior was likely to reflect a goal of the person or a trait of that person. In all of the studies, participants gave their own explanation for the behavior, which was then coded. The results were consistent with the researchers’ expectations.

When a behavior happens consistently and/or when it happens across situations, then people increase their belief that the behavior reflects a trait of the person, and they generate explanations of behavior that focus on traits. When a behavior happens inconsistently and/or when it happens in just a few situations, then people increase their belief that the behavior reflects a specific goal of the person, and they generate descriptions that focus on specific goals someone is trying to achieve.

Next time you’re watching someone do something unexpected, think about the explanations you give for their behavior. Get to know whether you make judgments about people’s traits or their goals and when you do each.