Though weighing the pros and cons of a purchase sounds like a purely rational, even mechanical act, this experiment suggests that the way the brain actually does the weighing is through a contest of conflicting feelings. Even the factor of price—a purely quantitative index, the kind of thing that is easily fed into a computer’s decision-making algorithm—ultimately enters the equation in the form of a feeling, a degree of aversion. And the stronger feeling—attraction or aversion—wins.
