The Calorie Heuristic: Food, Security, Love
Jonah Lehrer writes a nice column called “The Frontal Cortex,” for Wired magazine. His latest is about why we eat too much, and the answer is: Because we co-mingle sustenance and status in our minds. Lehrer covers some of the same territory I survey in On Second Thought, in the chapter called The Calorie Heuristic: Will Work for Food. Here’s a taste:
“I grew up with a brother who was very close to me in age, and we were both hyper-vigilant about getting our fair share. It didn’t matter what was at stake, but we were at our most deadly serious when it came to dessert. My mother had all sorts of clever tricks for dealing with this constant competition. If we were bickering over a last piece of pie, for example, she would randomly pick one of us to cut the slice of pie in half. But before the cutting started she would add: “And your brother gets to choose the slice he wants.”
Damn. With those few words, she took all the fun out of holding the knife, and indeed she probably shifted the competitive advantage. In any case, she made a muddle of self-interest and fairness in our young minds.
Well, it turns out my mother didn’t invent the pie-slicing gambit. Indeed, humans have been dividing up pies of all sorts, actual and metaphorical, for eons. For our earliest ancestors, food was the original cash. In the eons before minimum wages and credit cards and 401-Ks and Wall Street bailouts, the closest thing to earnings and savings was bounty from the hunt. Food was more than nourishment; it was an asset, currency of exchange. So it’s no wonder that the two resources remain inextricably connected and interchangeable in our modern minds today. Food equals money equals food.
So it’s probably no mistake that economists use so many pie diagrams to represent everything about money and wealth and budgets. That’s a reflection of the calorie heuristic, the brain’s tendency to entwine food and cash and fairness. Even though my mother did not originate the fairness trick, she was recognizing in her competitive children a well established (and fairly cynical) view of life. That view assumes that we all act like rational calculating machines, governed entirely by utilitarian self interest. But is this true? Is fairness simply a ruse, something we adopt only when we secretly see an advantage in it for ourselves? And do we expect no more than self-interest of others? Or is there such a thing as fairness for fairness’ sake?
Many psychologists have in recent years moved away from the purely utilitarian view, dismissing it as too simplistic. But the trick is in demonstrating genuine fairness in action, uncontaminated by self-serving motives like greed and need. Recent advances in both cognitive science and neuroscience now allow psychologists to approach this question in some different ways, and they are getting some intriguing results.
I’ll get to the calorie connection shortly, but first let’s look at a simple study of fairness and self-interest, this one using a classical psychological test called the “ultimatum game.” UCLA psychologist Golnaz and her colleagues used a version of the game that goes like this: Person A has a pot of money, say $23, which he can divide in any way he wants with Person B. All Person B can do is look at the offer and accept or reject it; there is no negotiation. If he walks away from the deal, there is no deal and neither person gets any money. In the laboratory experiment, there is no real Person A: It’s secretly the experimenter, making a range of offers, from generous to fair to stingy. The experimental subjects get to weigh the offers and respond.
Whatever Person A offers to Person B is an unearned windfall, even if it’s a miserly $5 out of $23, so a strict utilitarian would take the money and run. But that’s not exactly what happens in the lab. The UCLA scientists ran the experiment with different dollar amounts, so that sometimes $5 was stingy and other times fair, say $5 out of a total stake of $10. The idea was to make sure the subjects were responding to the fairness of the offer, not to the amount of the windfall. When they asked the subjects to rate themselves on a scale from happy to contemptuous, they had some interesting findings: Even when they stood to gain exactly the same dollar amount of free money, the subjects were much happier with the fair offers and much more disdainful of deals that were lopsided and self-centered. Indeed, many people actually reject very unfair deals, even though they lose out on free money, suggesting that their sense of decency trumps their rational, calculating mind. They respond emotionally to the idea that someone would take advantage of them.
That’s interesting in itself. But it could simply mean that we don’t like being treated shabbily, which wouldn’t be all that surprising. The psychologists want to know if, beyond that, there is something inherently rewarding about being treated decently. They decided to look inside the brains of these people to find out. They scanned several parts of their brains involved in aversion and reward while the subjects were in the act of weighing both fair and miserly offers, and they found that, yes, both parts of the brain light up during the ultimatum game. The brain finds self-serving behavior emotionally unpleasant, but a different bundle of neurons also finds genuine fairness uplifting. What’s more, these emotional firings occur in brain structures that are fast and automatic, so it appears that this impulse for fairness is primitive and ingrained, not rational. Faced with a conflict, the brain’s default position is to demand a fair deal.
So unfairness is fundamentally jarring to the brain, and fairness is fundamentally rewarding. This internal sense of equity is so basic, in fact, that scientists recently discovered it in dogs. Researchers at the University of Vienna studied well-trained and obedient dogs, rewarding them (or not) for shaking hands. When the dogs were tested alone, they offered their paws even without “payment” in the form of sausage or bread. But when they were next to another dog that got a reward when they did not, they became less and less inclined to obey the command. It was not the reward itself, but the perceived sense of inequity, that disturbed them.
Yet people do accept offers every day in real life that are less than equitable, and indeed they did so in the ultimatum game studies. When the scientists scanned the brains of those who were “swallowing their pride” for the sake of cash, the brain showed a distinctive pattern of neuronal firing. It appears that we can temporarily damp down the brain’s contempt center, in effect allowing the rational, utilitarian brain to rule, at least momentarily. So it seems contempt does not go away when the economic pie is sliced unfairly, it just goes underground.
So how are all our basic needs and behaviors—hunger and gluttony and frugality and charity and stinginess—connected in the brain? Put simply: Could comfort food translate into feelings of financial security? Might there be a link between satiety and generosity? Can we literally be hungry for money? Psychologists at Katholieke Universiteit Leuven in Belgium have been exploring this dynamic. Barbara Briers and her colleagues did a series of three experiments designed to tease apart the connections between nourishment and personal finances. In the first, they deprived some people of food for four hours, long enough that they wouldn’t be starving but they would almost certainly have food on their mind. Others ate as usual. Then they put all of them in a real-life simulation where they were asked to donate to one of several causes. Those with the growling stomachs consistently gave less money to charity, suggesting that when people sense scarcity in one domain, they conserve resources in another. Put another way, people with physical cravings are in no mood to be magnanimous.
In the second study, Briers actually let the participants eat as usual, but with some she triggered their appetites by wafting the scent of baked brownies into the lab. Then they played a computer game that, like the earlier simulation, tested their generosity. Again, those with food on their minds were less willing to part with their cash. Interestingly, in this study none of the participants was actually hungry, meaning that the desire for brownies alone was powerful enough to make them into tightwads.
That’s pretty convincing evidence. But the psychologists decided to look at it the other way around. That is, they wanted to see if a heightened desire for money affected how much people ate. They had participants fantasize about winning the lottery, but some imagined winning big (the equivalent of about $25,000) while the rest thought about a much more modest prize (about 25 bucks). The researchers wanted the more outlandish fantasy to increase desire for money, so they had the winners further fantasize about what this imaginary windfall would buy them—sports cars, stereos, and so forth. They basically made some of the participants greedy and not others.
Then they had all the participants participate in a taste test of two kinds of M&Ms, although unbeknownst to them the scientists were actually measuring how much they ate. And yes, the greedy people scarfed down significantly more candy. It appears that the desire to accumulate money (and stuff) is a modern version of the ancient adaptation to accumulate calories. (Significantly, however, people who were watching their weight did not break their diets, even if they were salivating for a large-screen TV: evidence that we can indeed trump our automatic thinking if we’re motivated and thoughtful.)
That last experiment echoes a classic study from the 1940s. In that study, poor kids consistently overestimated the size of coins, while rich kids did not. The new findings are also consistent with cross-cultural studies showing that men’s preference for the curviness of women’s figures varies directly with the men’s economic status. Psychologists Leif Nelson and Evan Morrison demonstrated this intriguing connection in the lab: In one experiment, they recruited a large group of students from campus and asked them how much money they had in their wallets. They figured that those with no cash would be less satisfied, financially, than those with spending money.
Then they asked them about their preferences for body weight in a dating partner. When they analyzed all the information, they found that men without money desired women who were significantly heavier than did men with bulging wallets. This was the first laboratory evidence that thinking about one’s financial situation affects dating preferences.
The psychologists decided to take another look at these initial findings, in a slightly different way. Instead of asking about ready cash, they asked the volunteers how much money they had socked away in the bank. But they asked some of them to place themselves on a scale of $0 to $500, while others placed themselves on a scale from $0 to $400,000. The idea was to manipulate their sense of relative scarcity: Some would feel kind of rich compared to others, while others would feel somewhat deprived. Then they again asked them about their preferences in partners, and again they found that those feeling flush wanted skinnier women. The men with a sense of life’s scarcity wanted their women to carry some extra pounds, almost as if their partner’s fat could protect them against starvation.
What’s the dynamic here? What explains this odd mental link? Nelson and Morrison think it has to do with actual hunger; that is, lack of cash or savings triggers the physiological state we all associate with too little food, and that sense of want triggers a basic need for more calories, more fat. To test this idea, the researchers parked themselves at the door of the Stanford dining hall and handed out questionnaires about dating to diners, some as they entered and others as they left. The idea was that some would be satiated when they thought about dating, while others would have food on their minds. And indeed the hungry men preferred more full-figured women.
The calorie heuristic is the brain’s ancient link among food and money and fairness. Both food and money are rewards, they give pleasure, and it’s possible that both (and perhaps other rewards as well) are processed in the same clusters of neurons devoted to savoring rewards. Whatever the underlying neurology, the findings could help explain a phenomenon that has long perplexed public health officials: the high prevalence of life-threatening obesity among society’s most disadvantaged. It seems counterintuitive that those with the least money should be consuming more calories. But it may be, Briers suggests, that material success has become so important that when people fail in their quest for money, they get frustrated and their brains switch between two intertwined rewards. In effect, they’re reverting back to a primitive state, when high-calorie food was the common currency. So those living hand to mouth do indeed work for food, but unhappily just not nutritious food.
This ancient and automatic entwining of food and money can skew our diets in other ways as well. Consider this bit of trivia: Americans typically eat yogurt out of 8-ounce containers. By contrast, the typical yogurt in a French market weighs less than five ounces. This seemingly pointless fact may hide a fundamental psychological truth about how humans regulate their consumption; in fact, how we make all sorts of choices in life.
That at least is the theory of University of Pennsylvania psychologist Andrew Geier and his colleagues, who are studying what they label “unit bias.” The number one, they argue, is a “natural unit,” and in the realm of food and diet that means one serving. The French don’t double up on their tiny yogurts to get the same volume of food or caloric intake as Americans. Instead, they simply stop eating after one serving, and therefore eat less overall, and therefore are more slender and healthier than overweight Americans.
That’s a heavy social burden for a simple yogurt container to carry. So Geier and colleagues decided to test the power of one in everyday settings. They did three similar experiments: In one, they put out a bowl of Tootsie Rolls for public consumption; some days the Tootsie Rolls were large, and other days they were small. They did the same test with Philadelphia-style soft pretzels; some days they put out whole pretzels, while other days they cut them in half. Finally, they put out a large bowl of M&Ms, alternating a tablespoon-sized serving spoon with a spoon four times that size.
The results were indisputable. Whatever their junk food of choice, people helped themselves to substantially more when they were offered supersized portions. And conversely, offering small portions effectively controlled how much people ate.
Why are snackers so mesmerized by the number one? It’s probably because the idea of one is so fundamental to identity and all the basic tasks of life. Each of us is one person, and most of us have one partner, one shelter, and so forth. But this deep-seated bias is probably reinforced by the forces of experience and culture. Many American children, for instance, are indoctrinated from early on to “clean their plates,” reinforcing the notion that a plateful is the appropriate amount to eat at a meal. And people may also limit themselves to one serving so as not to appear greedy or gluttonous.
Whatever the dynamic at work, the researchers believe that the unit bias affects many choices we make every day. We typically go to one movie, not two, whether the movie is 90 minutes long or three hours. We only ride the roller coaster once at the amusement park, regardless of the ride’s length. The unit bias is also the foundation of the most successful drug and alcohol recovery programs, which recognize the deep-seated need to focus on “one day at a time.”
But the most obvious implications of these snack-food experiments are in the public health arena, where overeating and obesity increasingly threaten Americans’ well being. Remember the Dagwood sandwich? Some readers will recall the comic strip Blondie, in which the lazy husband and father, Dagwood Bumstead, eats very tall sandwiches, layers upon layers of lunch meat and cheese and vegetables and bread. It’s a caricature of the unit bias in action.
Interestingly, food marketers appear to have picked up on this bit of psychological insight—in both good ways and bad. Many restaurants continue to attract customers with enormous Dagwood-sized “units,” as if those were normal healthy helpings. One minor league ballpark in Michigan sells a 4-pound, 4800-calorie cheeseburger for $20—that’s about twice the calories I consume in an entire day. That gross example of a “meal” might be dismissed as a publicity stunt, but the fact is that many offerings at fast-food chains are only a bit less exaggerated in their notion of a serving.
But a few food companies are capitalizing on the unit bias in healthier ways. For example, a couple years ago the Nabisco Company started selling junk food in 100-calorie “snack” units. Weight-conscious Americans loved then to the tune of $100 million a year, and many other food companies soon followed suit. Now we can get everything from Pringles to Sprite to Chips Ahoy in prepackaged 100-calorie snacks. Chips are still chips, but it’s better than pigging out on a family-size unit.
My mother also knew this intuitively. My family was always pinching pennies when I was growing up, and my mother was a very frugal grocer shopper. One thing she did was buy snack food in “economy size” or “family size” packages; she didn’t need a calculator to know that this was a smarter way to buy pretzels and chips by the ounce. But she didn’t stop there. As soon as she got home and put away the perishables, she would repackage the snacks, tossing the economical bags and dividing the contents into much smaller units, which she would seal up in plastic sandwich bags. By doing this, she was in effect telling us the proper portion or serving to eat at any given time. To her, moderation and fairness were the same thing.
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