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We should not argue when we’re mad because we might end up shouting things we don’t really mean and making a big mess. But due to the inner workings of our brain, not only are we more likely to lose control of our behaviors when angry, we may also lose control of our beliefs.
Here’s how it works:
Imagine you’re driving through a crowded grocery store parking lot when a man on a cell phone steps out in front of you. While holding the phone to his ear, he holds up a hand toward you, palm out. What does he mean by this gesture? And what is the appropriate response? Should you show him your palm in return, or, maybe another less polite gesture would be more appropriate?
How you interpret the man’s gesture—an apology, a thank-you, or a command—depends in large part on your own mood. If you’re in a bad mood, you’re more likely to see this man’s palm as an insistence of his entitlement to walk through traffic while yakking on his phone. If you’re in a good mood, you’re more likely to give him the benefit of the doubt and see his gesture as an apology for the inconvenience and a thank you for not turning him into a pavement pancake.
This is due to something called the mood congruency effect, and it means that when you feel bad and nasty, you think other people feel bad and nasty. That makes sense, but the thing is, not all flavors of bad and nasty look the same in your brain. Anger lives in your amygdala—it’s the “lizard brain” flavor of bad mood that cranks up your pulse, blood pressure, and secretion of epinephrine. But sadness lives in the hippocampus—it’s a more cognitive experience of bad mood that draws on memory and your interpretation of experiences, without necessarily affecting your body.
Do angry people interpret social cues differently than sad people do? Galen Bodenhausen, a professor of psychology at Northwestern University examined this question.
First he asked college students to “vividly recall an episode that had made them feel very angry, and describe in detail how the event occurred” (European Journal of Social Psychology). He had other students do the same thing with a sad memory. These prompts have been shown to prime these moods, making the first group of students a little angrier and the other a little sadder. (A third, control group was allowed to keep whatever mood they brought with them to the lab.)
Then Bodenhausen had students imagine that they were sitting on a peer-review panel judging cases of student misconduct—one involving cheating and one involving assault. In half of these cases, the fictional defendant was given an obviously Hispanic name. How did these sad, mad, or neutral students judge their Hispanic (and race-neutral) peers? Unfortunately, as you may have guessed, when college students were angry, but not when they were sad or neutral, they were much more likely to see guilt in peers with Hispanic names, but not more likely to see guilt in cases that included an accused person with a race-neutral name.
To Bodenhausen, this is evidence of “heuristic information processing": When you’re angry, instead of using your rational brain, you go with your gut, which, in this case of students’ intuition, included stereotypes. In other words, anger made students lose their minds, letting their “lizard brains” decide who was guilty.
Then Bodenhausen did the same thing with persuasion. He again primed college students to be angry, sad, or neutral, and then had them read an essay arguing to raise the legal driving age from 16 to 18. Half the college students were told that the essay had been written by “a group of transportation policy experts from Princeton University,” and half were told it had been written by “a group of students at Sinclair Community College in New Jersey.” How persuasive did college students find these arguments? It turned out that sad students left their rational brain in charge and formed their opinions largely on the content of the written argument; for angry students, the source of the argument trumped the content. Bodenhausen found the same thing when he varied the source's trustworthiness rather than expertise: When information came from a biased source, angry students let their distrust of the source overwhelm the information, whereas sad and neutral students distrusted the source but still based their opinions on the content of the argument.
In other words, when you’re angry, an argument becomes about the person and not the situation. You probably already knew that anger blunts your ability to be rational. But anger blunts rationality in a very interesting way: It seemingly opens a direct channel of communication to your biases, instincts, and heuristics—to all the beliefs and decision-making rules of thumb that are your fallbacks when not overridden by your more polite and rational conscious mind.
If you argue with your partner while you’re angry, your opinion of that person as idiotic and untrustworthy trumps anything smart or real or insightful he or she could possibly say. On the other hand, if you’re trying to stay focused on your side of a problem in the face of a charismatic and persuasive partner, your anger may make you more easily persuaded.
You can argue when you’re sad and still stay logical. But arguing when you’re mad puts your lizard brain in the driver’s seat and, too often, your best interests in the trunk.
For more usable tips from the science of your self, check out the book Your Daily Brain.
