Most people dream enthusiastically at night, their dreams seemingly occupying hours, even though most last only a few minutes. Most people also read great meaning into their nocturnal visions. In fact, according to a new study in the Journal of Personality and Social Psychology, the vast majority of people in three very different countries India, South Korea and the United States believe that their dreams reveal meaningful hidden truths.
According to the study, 74% of Indians, 65% of South Koreans and 56% of Americans hold an old-fashioned Freudian view of dreams: that they are portals into the unconscious. (See the top 10 scientific discoveries of 2008.)
But after so many years of brain research showing that most of our everyday cognitions result from a complex but observable interaction of proteins and neurons and other mostly uncontrolled cellular activity, how can so many otherwise rational people think dreams should be taken seriously? After all, brain activity isn't mystical but for the most part highly predictable.
The authors of the study psychologists Carey Morewedge of Carnegie Mellon University and Michael Norton of Harvard offer a few theories. For one, dreams often feature familiar people and locations, which means we are less willing to dismiss them outright. Also, because we can't trace the content of dreams to an external source because that content seems to arise spontaneously and from within we can't explain it the way we can explain random thoughts that occur to us during waking hours. If you find yourself sitting at your desk and thinking about a bomb exploding in your office, you might say to yourself, "Oh, I watched 24 last night, so I'm just remembering that episode." But people have a harder time making sense of dreams. Maybe 24 caused the dream, we think or maybe we're having a premonition of an attack. We love to interpret dreams widely, and those acts of interpretation give dreams meaning. (Read "Can't Sleep? Turn Off the Cell Phone!")
Human beings are irrational about dreams the same way they are irrational about a lot of things. We make dumb choices all the time on the basis of silly information like racial bias or a misunderstanding of statistics or dreams. Morewedge and Norton quote one of the most famous modern studies to demonstrate our collective folly, from a paper written by psychologists Amos Tversky and Daniel Kahneman that was published in Science in 1974. In that paper, Tversky and Kahneman discuss an experiment in which subjects were asked to estimate the percentage of African countries represented in the U.N. Before they guessed, a researcher spun a wheel of fortune in front of them that landed on a random number between 0 and 100. People tended to pick an answer that wasn't far from the number on the wheel, even though the wheel had nothing to do with African countries.
Countless experiments over the ensuing decades have confirmed that most of us make this so-called anchoring mistake that is, making a decision based largely on an unrelated piece of information, like a random number that appears on a wheel. Anchoring occurs all the time, like when you're asked to look at your Social Security number before answering a question (you're more likely to pick an answer close to the digits in your SSN). A team of researchers even showed in a 2003 paper in the Quarterly Journal of Economics that people will endure more physical discomfort (exposure to an unpleasant noise) for less monetary compensation in a lab setting when they are anchored prior to the experiments to smaller monetary amounts. As I said, we all make dumb choices based on silly information. That's why we invest meaning in dreams. (See TIME's 2004 cover on the science of sleep.)
That being said, dumb choices aren't necessarily bad ones. A final finding from the study: When people have dreams about good things happening to their good friends, they are more likely to say those dreams are meaningful than when they have dreams about bad things happening to their friends. Similarly, we invest more meaning in dreams in which our enemies are punished and less meaning in dreams in which our enemies emerge victorious. In short, our interpretation of dreams may say a lot less about some quixotic search for hidden truth than it does about another enduring human quality: optimistic thinking.