Whether you’ve read Malcolm Gladwell’s hugely popular book Blink or not, you’ve probably heard what it’s about: In some cases unconscious thought is more powerful than conscious thought; a decision made in a split-second may be more accurate than one deliberated over for an hour. As attractive as these ideas may be, a new study which investigated the so-called unconscious thought advantage arrives at a verdict that will likely sadden Gladwell and his many fans.

“We conclude that there exists no reliable support for the claim that a momentary diversion of thought leads to better decision-making than a period of deliberation,” write the authors in their recently published paper.

For their analysis, Drs. Mark Nieuwenstein and Hedderik van Rijn, both psychologists at the University of Groningen, combined an original experiment with a review of past studies. They asked 399 participants — about 10 times the average sample size in other studies — to choose between either four cars or four apartments on the basis of 12 unique features. Having scrutinized past experiments, they incorporated conditions that supposedly yield the strongest unconscious thought advantage (UTA) effects, such as an exact type of puzzle used as a distraction.

However, despite designing a study weighted in favor of UTA effects, participants in the distracted group were no more likely than those in the deliberating group to choose the most desirable car or apartment. Unconscious thought, then, failed to trump conscious thought. Next, the research team reanalyzed 60 of the 81 experiments described in 32 published UTA papers. While including the results of their own study, they excluded those experiments that had insufficient data or that deviated from conditions highly favorable to UTA. Despite these exclusions, they discovered UTA theories do not hold water when investigated under rigorous statistical analysis.

Never Say Die

Dr. Ap Dijksterhuis, one of two psychologists who first described unconscious-thought theory, does not accept the new findings. In a recent Nature article, he says his theory is widely accepted and “the evidence for UTA is growing quickly.”

In his 2004 paper, he and Dr. Loran F. Nordgren described two modes of thought, unconscious and conscious, while further stating the different characteristics of these two modes suggest each is "more or less useful" under different circumstances.

“This theory proposes that the best way to make a difficult decision is to refrain from painstaking conscious deliberation and to let one’s unconscious mind solve the problem while one engages in more enjoyable activities such as solving a crossword puzzle,” wrote Dijksterhuis and Nordgren, adding, “this theory claims the existence of an unconscious form of thought that has a much greater information-processing capacity than conscious thought.” For this reason, they assert it is in your best interest to let “the clever unconscious mind” take charge and solve specific difficult problems.

“The idea that a momentary diversion of thought leads to better decision making than a period of deliberation remains an intriguing but speculative hypothesis that lacks empirical support,” write the authors in their conclusion. Once again, a fun idea takes a dive.

Source: Nieuwenstein MR, Wierenga T, Morey RD, et al. On making the right choice: A meta-analysis and large-scale replication attempt of the unconscious thought advantage. Judgment and Decision Making. 2015.