The first line of Aristotle’s Metaphysics begins with a seemingly obvious truth: “All men by nature desire to know.” According to Aristotle, this desire for knowledge is our defining instinct, the quality that sets our mind apart. As the cognitive psychologist George Miller put it, we are informavores, blessed with a boundless appetite for information.

It’s a comforting vision. However, like all dictums about human nature, it also comes with plenty of caveats and exceptions. Take spoiler alerts. It’s hard to read an article about a work of entertainment that doesn’t contain a warning to readers. The assumption of these warnings, of course, is that people don’t want to know, at least when it comes to narratives.

And it’s not just the latest twists in Scandal that we’re trying to avoid. Twenty percent of Malawi adults at risk for HIV decline to get the results of their HIV test, even when offered cash incentives; approximately 10 percent of Canadians with a family history of Huntington Disease choose to not undergo genetic testing. (Even James Watson declined to have his risk of Alzheimer’s revealed.) These are just specific examples of a larger phenomenon. Given the advances in genetic testing and biomarkers, the Aristotelian model would predict that we’d all become subscribers to 23andMe. But that’s not happening.

A new paper in Psychological Review by Gerd Gigerenzer and Rocio Garcia-Retamero explores the motives of our willful ignorance. They begin by establishing its prevalence, surveying more than 2000 German and Spanish adults about various forms of future knowledge. Their results are clear proof that most of us want spoiler alerts for real life: between 85 and 90 percent of subjects say they don’t want to know when or why their partner will die. (They feel the same way about their own death.) They also don’t want to know if their marriage will eventually end in divorce. This preference for ignorance even applies to positive events: between 40 and 70 percent of subjects don't want to know about their future Christmas gifts, or who won the big soccer match, or the gender of their next child.

To understand our reasons for ignorance, Gigerenzer and Garcia-Retamero asked subjects about their risk attitudes. They found that people who are more risk-averse (as measured by their insurance purchases and their choices playing a simple lottery game) are more likely to prefer not knowing. While this might appear counterintuitive—learning how you will die might help reduce the risk of dying— Gigerenzer and Garcia-Retamero explain these results in terms of anticipatory regret. People avoid risks because they don’t want to regret those losing gambles. They avoid life spoilers for a similar reason, as they're trying to avoid regretting the decision to know.

On the one hand, this intuition has a logical sheen. It’s not that ignorance is bliss—it’s just better than knowing that life can be shitty and full of suffering. Knowing exactly how we’ll suffer might only make it worse. The same principle also applies to the good stuff: we think we'll be less happy if we know about our happiness in advance. Life is like a joke—it's not so funny if we get the punchline first.

But there’s also some compelling evidence that our intuitions about regretting future knowledge are wrong. For one thing, it’s not clear that spoilers spoil anything. Consider a 2011 study by Jonathan Leavitt and Nicholas Christenfeld. The scientists gave several dozen undergraduates twelve different short stories. The stories came in three different flavors: ironic twist stories (such as Chekhov’s “The Bet”), straight up mysteries (“A Chess Problem” by Agatha Christie) and “literary stories” by writers like Updike and Carver. Some subjects read the story as is, without a spoiler. Some read the story with a spoiler carefully embedded in the actual text, as if Chekhov himself had given away the end. And some read the story with a spoiler disclaimer in the preface.

Here’s the shocking twist: the scientists found that almost every single story, regardless of genre, was more pleasurable when prefaced with some sort of spoiler. It doesn’t matter if it’s Harry Potter or Hamlet: an easy way to make a good story even better is to spoil it at the start. As the scientists write, “Erroneous intuitions about the nature of spoilers may persist because individual readers are unable to compare spoiled and unspoiled experiences of a novel story. Other intuitions about suspense may be similarly wrong: Perhaps birthday presents are better when wrapped in cellophane, and engagement rings when not concealed in chocolate mousse.”

In fiction as in life: we assume our pleasure depends on ignorance. However, Leavitt and Christenfeld argue that spoilers enhance narrative pleasure by letting readers pay more attention to developments along the way. Because we know the destination, we’re better able to enjoy the journey.

There's more to life than how it ends.

Gigerenzer, Gerd, and Rocio Garcia-Retamero. "Cassandra’s regret: The psychology of not wanting to know." Psychological Review 124.2 (2017): 179