We hope that thinking about a decision results in a good choice, and that the more complex the decision, the more time and effort were invested in thinking about it. Scientists show that deliberate thinking about simple decisions (such as buying a shampoo) does yield choices that are judged to be more satisfying than those made with little thought, as expected. However, as the decisions become complex (more expensive items with many characteristics, such as cars), better decisions and happier ones come from not attending to the choices but allowing one’s unconscious to sift through the many permutations for the optimal combination.

researchers report a series of experiments with student volunteers and real-life shoppers that suggests that too much contemplation gets in the way of good decision-making–especially when the choice is complicated.

Contrary to conventional wisdom, it is not always advantageous to engage in thorough conscious deliberation before choosing. On the basis of recent insights into the characteristics of conscious and unconscious thought, we tested the hypothesis that simple choices (such as between different towels or different sets of oven mitts) indeed produce better results after conscious thought, but that choices in complex matters (such as between different houses or different cars) should be left to unconscious thought. Named the “deliberation-without-attention” hypothesis, it was confirmed in four studies on consumer choice, both in the laboratory as well as among actual shoppers, that purchases of complex products were viewed more favorably when decisions had been made in the absence of attentive deliberation.