Andrea Morales and Gavan Fitzsimons can both remember when and where their current research interest began. It came during a talk at the University of Pennsylvania a few years ago: Paul Rozin, a professor of psychology, took a cockroach that had been sterilized, dipped it into a glass of orange juice, then asked if anyone was willing to take a sip.
Nobody was. But if an involuntary ewww just went through your mind, as it almost certainly did, the experiment is still working. Rozin specializes in the psychological study of disgust, and he was demonstrating the universal concept of touch transference. It's a fancy term for cooties. If something repulsive touches something benign, the latter, even if it's physically unchanged, becomes "infected."
Fitzsimons and Morales, who teach marketing at Duke and Arizona State University, respectively, suspected this phenomenon had implications for the consumer marketplace--and in an article in this month's Journal of Marketing Research, they show that it does. In a series of studies, the researchers found not only that some products--trash bags, diapers, kitty litter, tampons--evoke a subconscious feeling of disgust even before they're used for their ultimate messy purposes, but they can also transfer their general ickiness to anything they come in contact with. "We were pretty surprised at how strong the effect was," says Fitzsimons. "This is probably the most robust result in my career."
It's also part of a growing trend of applying science to supermarkets (see chart). Analysts who study shopping habits have already made some surprising discoveries about product placement. "Eye level," for example, used to mean, not surprisingly, "at the level of the eyes." But shoppers tend to keep their eyes aimed at cart level much of the time, making sure they aren't about to run over another customer. And because Americans read from left to right, shelf-stockers tend to put name brands like, say, Heinz, on the left side of the ketchup display, and the lesser known, more profitable in-house brand on the right.
This may be the first study, though, that reveals an evolutionary basis to shopping preferences. Low-threshold revulsion makes sense, protecting our ancestors from eating rotten or poisonous food or touching animals that had died of infectious disease. The face of disgust--with the nose wrinkled and the eyes squinted as if against some pungent smell, and the tongue often protruding as if spitting something out--tells you a lot. "It was probably," says Fitzsimons, "a pretty good proxy for the germ theory of disease before anyone knew germs existed."
The idea that negative qualities can be passed by a touch has become hardwired, says Fitzsimons. (That applies to good qualities too, which is why touching a holy object or person is considered a way of acquiring a little holiness for oneself.) So he and Morales set out to see whether toilet paper and other products could psychologically contaminate food in a shopping basket. They used real shopping baskets, though they did not conduct their tests in a real supermarket, and told subjects that the study had to do only with product preference.
Strong preferences were just what the subjects exhibited. Any food that touched something perceived to be disgusting became immediately less desirable itself, though all of the products were in their original wrapping. The appeal of the food fell even if the two products were merely close together; an inch seemed to be the critical distance. "It makes no sense if you think about it," says Fitzsimons. More irrationally still, the subjects were less comfortable with a transparent package than an opaque one, as if it somehow had greater power to leak contamination. Whatever the severity of the taint, the result was predictable.
"We'd take cookies out of the basket and offer them to the subjects," says Fitzsimons, "and we had some really tempting-looking cookies." No takers. Moreover, he says, "everything we did suggested that these feelings were below the level of awareness. If we told someone, 'You didn't take the cookie because it touched the kitty litter,' they would say, 'That's ridiculous.'"
A product does not stay contaminated forever. The aversion tends to fade after about an hour, though that's not much use to the grocery store, since shoppers don't generally return a short while after leaving to reconsider their purchases.
Unlike a study in, say, particle astrophysics, this one has practical consequences. "More and more stores organize products by category," says Morales, "so you have a baby aisle, for example, with diapers and wipes and baby food all together." Supermarkets might want to rethink that arrangement. And other retailers will be interested to hear about Morales' next study, on the opposite of the cooties effect. "It turns out that if male customers see an attractive woman touching a garment, like a T shirt, the men are more likely to want it."