An interesting observation from this research is that people’s moral judgments are also related to disgust. When people witness (or hear about) a moral transgression, they often get a disgust reaction. In addition, feelings of disgust increase people’s sense of moral outrage. A fascinating element of this work is that the sense of moral outrage may increase even when the feeling of disgust comes from another source.

The idea is simple. As with most feelings, we look around the world trying to find the source of those feelings. Most of the time, those sources are obvious. Imagine you are walking down the street, and suddenly you see a car speeding toward you. You jump back onto the sidewalk, and feel a combination of (that you were almost hit) and relief (that you were not). It is pretty clear that the reason for these feelings is that you were almost hit by a car.

In some cases, the source is less obvious. You might wake up in the morning feeling some because you have an exam coming up or a big presentation at work. That underlying stress may make you about making a big purchase, even though the stress came from another source.

The same thing can happen with disgust. Encountering a disgusting situation can influence other judgments about morality. A fascinating set of experiments by Lotte Van Dillen, Reine van der Wal, and Kees van den Bos in the September, 2012 issue of and Social Psychology Bulletin explored individual differences in this tendency to misattribute disgust in moral judgments.

They pointed out that people differ in their level of attentional control. Consider the classic Stroop task. In the Stroop task, color words are written in fonts of different colors. People are asked to name the color of the font. The task is easy when the font is the same color named by the word. That is, people are fast to say that the font is red when the word is RED. The task is hard when the font is a different color than the one named by the word. So, people are slow to say that the font is red when the word is GREEN.

There are individual differences in how hard people find this task. Some people find it very hard to name the font when the word is different, while others are able to guide their toward the font color more exclusively and so they find the task easier.

In one experiment, the researchers told participants that they were going to do a series of unrelated experiments. First, they gave participants a Stroop task and measured the difference in speed for naming the font when the word named the same color or a different color. That speed was a measure of the ability to control attention. Next, participants read sentences that either described mildly disgusting events (“Ann bit into an apple and found a worm inside.”) or neutral events (“Ann bit into an apple that she brought for lunch.”).

Finally, participants read a story about someone who found a wallet and decided to keep it. They were asked to rate how strongly they disapproved of that action. Participants who read neutral sentences tended to rate this action as moderately severe. Participants who found it easy to identify the font color when the word named a different color (so they had a high degree of attentional control) also rated the action as moderately severe. However, those who found it hard to identify the font color when the word named a different color (so they had a low degree of attentional control) rated that they strongly disapproved of the action.

Another study in this series manipulated the instructions given to people viewing disgusting events. Some were told to feel as strongly as possible, while others were told to distract themselves while viewing the disgusting events. Later in the session, participants read a story about someone who leaves his/her family after having an affair and were asked how strongly they disapproved.

In this case, people who were asked to feel when viewing the disgusting events rated themselves as more disapproving of the person in the story than people who were asked to distract themselves.

Putting all of this together, then, you can use your sense of disgust to help you determine whether an action is morally right. You are prone to use any feeling of disgust you are experiencing to make this judgment. However, the higher the level of your ability to focus attention, the more likely you are to restrict your use of disgust to those feelings that are actually related to the event you are judging.

Follow me on Twitter.

And on Facebook and Google+.

Check out my book Smart Thinking (Perigee)