George Orwell wrote that To see what is in front of one s nose needs a constant struggle. He was writing, in 1946, about the end of World War II and the leaders of Germany and Japan being unable to see facts which were plain to any dispassionate eye. But the principle is a general one, as we seem to learn over and over, whether it s in business, politics, or our personal lives. Humans have a remarkable talent for seeing what they want to see.

But is this a controllable quirk? Something that only takes over when we re willfully blind to reality? Or is this a more basic feature of human cognition something we re incapable of turning off, that affects even our most fundamental perceptions of reality?

A new study in the journal Psychological Science offers some compelling evidence that the latter is closer to the truth. In their paper, Wishful Seeing, Emily Balcetis of New York University and David Dunning of Cornell report the results of their research showing that people are not only biased in their reasoning but are actually biased in their visual perception literally, how they see the world.

In a clever series of experiments, Balcetis and Dunning show that people reliably misperceive how far away an object is based on how much they desire it. That is, more desirable objects appear closer. In one study, the researchers had people sit across the table from a full bottle of water and then had them either eat pretzels or drink water from an eight-ounce glass. After being shown a one-inch line as a reference, the participants were then asked to estimate how many inches separated them from the bottle of water. Consistently, the thirsty participants perceived the water bottle as being closer than did the quenched participants.

To test this result further perhaps people s distance estimates were thrown off when they were thinking about how to estimate the distance, not by their actual perception of the distance the researchers set up another experiment to test people s distance estimates in a more physical way. In this experiment, participants were given the chance to win a $25 gift card or a $0 gift card by tossing beanbags at it. The person whose beanbag landed closest won the gift card. The $25 card, of course, was desirable the $0 card not so much. Once again, the researchers found that people underestimated the distance between themselves and the desirable object.

How pervasive is this effect? Pretty pervasive, as a growing body of research one that dates back to the late 1940s is starting to make clear.

In the late 1940s and 1950s, psychologists examined what s called the New Look approach to perception the idea that perception is a constructive process heavily influenced by an individual s desires, needs, and values. In a foundational study on the topic, psychologist Jerome Bruner and Cecile Goodman asked children to estimate the sizes of coins and cardboard circles (by using a contraption to make a circle of light on a cardboard box approximating the sizes of the objects they were being shown). What they found was that the children consistently judged the coins to be larger than the identically sized cardboard circles. This suggested that the kids were being influenced by the monetary value of the coins. Further strengthening this suggestion, kids from poorer backgrounds saw the coins as even bigger than kids from richer backgrounds did presumably because the poorer kids valued the coins more.

This perspective fell out of favor for a while, partly because the methodologies used to test it were seen to allow for too many alternate explanations (perhaps, for instance, the poor kids were just less familiar with coin sizes), but it s had a revival in recent years. Other recent research, for instance, has found that being older, fatigued, or weighed down by a big backpack makes people see hills as steeper and distances to visible landmarks farther away.

This biased perception isn t necessarily a bad thing. As an adaptation to our natural environment, in fact, it s seen as quite advantageous. Seeing a desirable thing, such as food, as closer can help motivate us to go and grab it. Conversely, seeing a distant place as farther away when laden down might help us avoid overexertion.

But this most human of flaws also gets us into trouble, at a deeper level. When a Martha Coakley sees a Scott Brown as no big threat, blind to popular discontent. When a Microsoft or a Blockbuster spends years seeing a Google or a Netflix as no big deal, blind to radical shifts in consumers habits. When a potential home buyer sees housing prices going up and is blind to all signs of an impending collapse. That s when our wishful seeing can be deadly.

Perhaps, in some of these cases, hindsight is 20/20. But, most of the time, we re not struggling hard enough to see what s in front of our noses.

Ryan Sager writes the blog Neuroworld at TrueSlant.com.