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The timeline of big moments in human history is littered with sudden, seemingly random realizations. Rene Descartes, for instance, came up with the idea for Cartesian geometry while watching a fly zoom around his bedroom. Paul McCartney wrote “Yesterday” after the fully formed tune plopped itself into his brain (“I woke up one morning with a tune in my head,” he later recalled, “and thought, ‘Hey, I don’t know this tune — or do I?’”) Then there’s the guy who gave the eureka moment its name: Archimedes, the ancient Greek mathematician who noticed when he settled in for a bath that the density of an object could be measured by the volume of water it displaced.

That’s not to say that these out-of-the-blue bolts of inspiration are experienced only by geniuses. They aren’t, as anyone who’s ever had a flash of brilliance in the shower can attest. (Archimedes, come to think of it, may have invented deep shower thoughts, too.) In 2010, researchers identified a few traits that all eureka moments have in common: They happen suddenly, they come easily, they feel like positive experiences. And perhaps most importantly, they feel right — you assume they’re true, even before you’ve had time to determine if that’s actually the case.

Often, though, the feeling is spot-on: An article in the May issue of Scientific American highlights recent research making the case that these eureka moments are usually right.

In one study, published in the journal Thinking and Reasoning, a team of researchers led by Northwestern University psychology Carola Salvi led participants through four different brain-teaser experiments. For the first, the subjects were given a set of three words and told to come up with the word that could combine with all three. For the set “crab,” “pine,” and “sauce,” for example, the word would be “apple” — crabapple, pineapple, applesauce. After each set, participants reported whether they’d solved the problem with insight (explained as “the answer suddenly coming to mind, being somewhat surprising, and with the participant having difficulty stating how the solution was obtained”) or analysis (“the answer coming to mind gradually, using a strategy such as generating a compound for one word and testing it with the other words, and being able to state how the solution was obtained”).

When the researchers crunched the numbers, they found that around 94 percent of the problems that had been solved with insight had been solved correctly, versus just 78 percent for problems solved with analysis — a pattern that held across the following three experiments, too. Each time, the subjects were given some sort of word or picture puzzle to solve; each time, insight proved to be a more successful strategy than methodically thinking it through.

Part of the discrepancy, as Scientific American explained, likely stems from the fact that insight and analysis are distinctly different processes in the brain:

Because such processing occurs largely outside a person’s awareness, it is all or nothing—a fully formed answer either comes to mind or it doesn’t. This hypothesis is supported by EEG and functional MRI scans, which revealed in previous studies that just before insight takes place, the occipital cortex, which is responsible for visual processing, momentarily shuts down, or “blinks,” so that ideas can “bubble into consciousness,” [psychologist John] Kounios says. As a result, insights are less likely to be incorrect. Analytical thinking, in contrast, happens consciously and is therefore more subject to rushing and lapses in reasoning.

Past research has described sudden insight, in contrast to conscious analysis, as an “all or nothing” system: In timed lab experiments, when someone using insight to solve a problem fails to arrive at the correct answer, it’s often because they let the time elapse without venturing a guess; when they’re using analysis, it’s more likely they offered several wrong answers along the way. The caveat, of course, is that things like Cartesian geometry and “Yesterday” aren’t timed lab experiments, and existing research can’t speak much for the sudden bursts of creativity that take place in the real world. So maybe take your shower thoughts with a grain of salt, but that doesn’t mean you shouldn’t keep on letting your mind wander while you shampoo.