The (Honest) Truth About Dishonesty

Within a block of your new place are three restaurants. One is a little bistro with fresh salads and paninis. Another is a Chinese place; the greasy, salty smells emanating from within make the back of your mouth tingle. There’s also a cute mom-and-pop pizzeria where the locals enjoy cheesy slices twice the size of their faces. To which restaurant do you drag your tired, aching body? Which kind of cuisine would you prefer to enjoy on your new floor? By contrast, consider what your choice might be if the meal were after an afternoon spent relaxing in the backyard with a good book.

In case you haven’t noticed, on stressful days many of us give in to temptation and choose one of the less healthy alternatives. Chinese takeout and pizza are practically synonymous with moving day, conjuring up an image of a young, attractive, tired, but happy couple surrounded by cardboard boxes and eating chow mein out of the box with chopsticks. And we all remember the times college friends offered us pizza and beer in exchange for helping them move.

This mysterious connection between exhaustion and the consumption of junk food is not just a figment of your imagination. And it is the reason why so many diets die on the chopping block of stress and why people start smoking again after a crisis.

Let Us Eat Cake

The key to this mystery has to do with the struggle between the impulsive (or emotional) and the rational (or deliberative) parts of ourselves. This is not a new idea; many seminal books (and academic papers) throughout history have had something to say about the conflicts between desire and reason. We have Adam and Eve, tempted by the prospect of forbidden knowledge and that succulent fruit. There was Odysseus, who knew he’d be lured by the Sirens’ song and cleverly ordered his crew to tie him to the mast and fill their ears with wax to muffle the tantalizing call (that way, Odysseus could have it both ways—he could hear the song without worrying that the men would wreck the ship). And in one of the most tragic struggles between emotion and reason, Shakespeare’s Romeo and Juliet fell hard for each other, despite Friar Laurence’s warning that untamed passion only brings disaster.

In a fascinating demonstration of the tension between reason and desire, Baba Shiv (a professor at Stanford University) and Sasha Fedorikhin (a professor at Indiana University) examined the idea that people fall into temptation more frequently when the part of their brain that is in charge of deliberative thinking is otherwise occupied. To reduce participants’ ability to think effectively, Baba and Sasha did not remove parts of their brains (as animal researchers sometimes do), nor did they use magnetic pulses to disrupt thinking (though there are machines that can do that). Instead, they decided to tax their participants’ ability to think by piling on what psychologists call cognitive load. Simply put, they wanted to find out whether having a lot on one’s mind would leave less cognitive room for resisting temptation and make people more likely to succumb to it.

Baba and Sasha’s experiment went like this: they divided participants into two groups and asked members of one group to remember a two-digit number (something like, say, 35) and they asked members of the other group to remember a seven-digit number (say, 7581280). The participants were told that in order to get their payment for the experiment, they would have to repeat the number to another experimenter who was waiting for them in a second room at the other end of the corridor. And if they didn’t remember the number? No reward.

The participants lined up to take part in the experiment and were briefly shown either the two-digit number or the seven-digit number. With their numbers in mind, they each walked down the hall to the second room where they would be asked to recall the number. But on the way, they unexpectedly passed by a cart displaying pieces of rich, dark chocolate cake and bowls of colorful, healthy-looking fruit. As participants passed the cart, another experimenter told them that once they got to the second room and recited their number they could have one of the two snacks—but they had to make their decision right then, at the cart. The participants made their choice, received a slip of paper indicating their chosen snack, and off they went to the second room.