We all know stupid when we see it (or do it). But what defines it? Researchers from Eotvos Lorand University in Budapest, Hungary and Baylor University recently teamed up to find a scientific answer. They published their findings in the aptly named journal Intelligence, thinking that the results might help us analyze our actions and prevent us from doing dumb things.

Since we are all “stupid” from time to time, the scientists had plenty of real-life case material to work with. According to Real Clear Science, they collected 180 stories that gave examples of stupid actions from both the Internet and the daily reports of 26 college students. To make sure the stories were short enough for analysis, easily understandable, and were actually “stupid,” a team of seven individuals vetted the actions.

Next, researchers had 154 college students rate the stories for “stupidity” on a 1–10 scale, using one of 12 questionnaires that cited 15 tales of foolishness. The raters were tasked with deciding which psychological factors contributed to the stupid action’s occurrence, how responsible the individual or environment was for causing it to arise, and whether any consequences followed.

The college students largely agreed on what was stupid and wasn’t. Researchers reviewed the data, and synthesized their findings into three categories. One way an action can be stupid, they wrote, is if “the actor takes high risks while lacking the necessary skills to perform the risky action”—say, if thieves accidentally took GPS navigation devices when they meant to steal cell phones, and were discovered because they forgot to turn them off. They dubbed this phenomenon “confident ignorance.”

The second criteria, “Absentmindedness—Lack of practicality,” would be familiar to any space cadets who forget to fill their gas tanks or pay their credit card bills on a regular basis. As for the third category, “Lack of control,” which stems from obsessive, compulsive, or addictive behavior, was responsible for brain-dead behavior. (One example: using a video game habit as an excuse to stand up a friend.)

And while we’re all guilty of stupid actions, researchers did find that people tend to judge us for them more if we assume a high level of responsibility or inflict serious consequences on anyone.

Of course, the study did have its limits; all participants were Hungarian college students, and about 79 percent of them were women. There are surely cultural variations on the concept of stupid. Still, at the end of the day, some things are just so universally, even fatally, dumb that virtually all of us will shake our heads in disbelief.   

[h/t Real Clear Science]