You're a man at a party, and two women are competing for your attention, a blonde and a brunette. The blonde has a wonderful sense of humour, but the brunette is sexier. Then a third woman joins you, another blonde, minus the sense of humour. She triggers what psychologists call "the asymmetric dominance effect" and you give the first blonde your phone number. What has this got to do with Frozen Coke, Coca-Cola's most recent offshoot? Quite a lot, according to Dan Ariely, a professor of psychology and business at the Massachusetts Institute of Technology.
Snack and soda moguls use new offerings such as Frozen Coke to get consumer attention. But they prefer "line extensions" - marginal variations on the existing formula - to genuinely innovative products, because line extensions don't risk eroding the brand. As a result, Coke now resembles the Habsburg family, a sprawling dynasty whose members all appear very much alike: Diet Coke, Cherry Coke, Diet Cherry Coke, Coke with Lemon, Diet Coke with Lemon, Vanilla Coke, Diet Vanilla Coke, and so on.
Line extensions often flop, from New Coke in 1985 and Crystal Pepsi in 1992 to Frozen Coke, which Burger King spent $65m to promote. But even if they fail, line extensions can boost sales of related drinks. Frozen Coke may have fizzled, but it boosted sales of Coke and Diet Coke.
This is the asymmetric dominance effect. When confronted by two disparate but equally weighted choices (A and B), we have trouble deciding. But if a third option is introduced that is similar to but slightly inferior to A, we'll pick A. Likewise, if the option is similar to but slightly inferior to B, we'll swing towards B. It makes a certain crooked sense. It's hard to say whether you prefer the amusing blonde or the sexy brunette, but easy to say you prefer the amusing blonde to the dull one.
It is difficult to see how this can be exploited socially, short of paying someone to hover at your elbow and masquerade as a slightly less appealing version of you. But whether or not it works at parties, the asymmetric dominance effect magnetises us when we're buying a soft drink. You might hover between Coke and Pepsi, but you know you prefer Coke to Frozen Coke. So you choose Coke.
We think we make choices based on pre-existing preferences and the merits of the options. But some psychologists argue that the "framing" of a choice strongly influences its outcome. In the supermarket, Coca-Cola, Nabisco and the other leading brands, wittingly or not, frame our choices. Our very nonchalance in choosing makes us easy to manipulate.
For while choice appears to be growing exponentially, it is shrinking on a macrocosmic level. The snack and soda industries are becoming ever-tighter oligarchies. Coke owns more than 300 beverage brands and is gobbling up more. PepsiCo has merged with Quaker. And as fewer companies control more of the market, we have less knowledge of the activities we underwrite with our purchases.
In any case, distant choices - whether or not to boycott a brand, for example - tend to preoccupy us less than immediate ones, especially as those choices become ever more fine-grained: between cappuccino and latte, Diet Coke with Lemon or Caffeine-Free Diet Coke with Lemon. The asymmetric dominance effect may not blind us to the power of multinationals. But it can distract us a little.