Her book is about the ways in which our bodies affect our brains. To show how, Beilock did a studythat sought to answer the question: When you decide whether or not you like an object, might you be making that decision based on how easy it is to pick the object up?
She put two kitchen objects – for example, a spatula and a spoon — in front of 15 undergraduate volunteers. The objects were placed in different positions — say, one with the handle facing the person, one with the handle pointed away.
She asked her volunteers to move the object they liked better into a box. Each person was given 16 tests. Each time, one of the objects was in an easier-to-pick-up position than the other.
You would expect a 50/50 breakdown. But the study, published in the journal Emotion Review, showed that 63 percent of the time people preferred the object that was easiest to grab.
So sure, your brain is making the decision, but the decision may be based not on whether you really like, say, a spoon more than a spatula, but simply on whether it looks easy to pick up.
"This means that subtle changes in the placement or packaging of products can have big effects on people's desire to buy them," she observes. And that's where soda bottles come in.
In 2008, Coke redesigned its two-liter bottle a few years ago to make it curvier and thus, "easier to hold and pour," in the words of a Coca-Cola representative. And suddenly, Beilock reports, Coke was selling a lot more of its two-liter sodas than archrival Pepsi.
Does this mean Coke knew all about the way the body influences the mind? Beilock says: "My guess is [in tests] people preferred that bottle."
Based on her research, she believes that the enticing shape of a soda bottle "might push you to buy it even knowing it's not the right decision." (Because after all, soda is not good for you. It falls into the category of what she calls "vice products.")
So the message for soda bottles is that shape matters. Size could matter, too. In December, Coca-Cola introduced a 350-milliter plastic soda bottle — that's a hair under 12 ounces — in parts of Kenya. The goal, according to Coca-Cola, is "to offer our consumers an affordable 'on the go' convenience pack." It's called the kashorty, a colloquial Swahili word that means "the short one."
The kashorty would be especially easy for small hands to pick up. "It could have an effect on kids," says Beilock. And the effect could be: We want soda!
In the developing world, where the invasion of sugary Western products is contributing to a rise in obesity and diseases associated with being overweight, the kashorty could reinforce the soda company's 1950s slogan "What you want is a Coke."