When faced with a difficult decision, we try to come up with the best choice by carefully considering all of the options, maybe even resorting to lists and lots of sleepless nights. So it may be surprising that recent studies have suggested that the best way to deal with complex decisions is to not think about them at all—that unconscious thought will help us make the best choices. Although this may seem like an appealing strategy, new research in Psychological Science cautions that there are limitations in the efficacy of unconscious thought making the best decisions.

Duke University researchers John W. Payne, Adriana Samper, James R. Bettman and Mary Frances Luce had volunteers participate in a lottery choice task, where they had to pick from four various options, each with a different, but close, payoff. The volunteers were divided into three groups for this task: one group was instructed to think about the task for a given amount of time, another group was told to think about the task for as long as they wanted and the last group was distracted before making their selection (thus, unconsciously thinking about the task). A second experiment was similarly set up, except that there were substantial differences in the payoffs of the different options.

The researchers found that there are situations where unconscious thought will not result in the best choice being selected. The findings showed that in some instances (when the payoffs were similar), thinking about the task for as only as long as it takes to make a decision was as effective as unconscious thought, resulting in the most profitable options being chosen. However, when there were large differences in the amount of money to be won, mulling over the decision at their own pace led the volunteers to larger payoffs than unconscious thought. The volunteers who were told to consciously think about the decision for a specific amount of time performed poorly in both experiments. The authors explain that those volunteers had "too much time to think" about the task and suggest that their attention shifted "to information of lesser relevance," resulting in less profitable decisions.

These results suggest that although unconscious thought may help us make the right decision in some instances, it is often better to rely on self-paced conscious thought and really focus on the problem at hand.