The theory is based primarily on findings from comparing subjects presented with a complex decision (for instance which of several apartments is the best?
It is claimed that subjects unable to devote conscious processing to the task outperform both those who can spend time deliberating and those who must respond immediately.
UTT is in this respect reminiscent of some classical views of the unconscious that emerged as far back as the early twentieth century.
Both UTT and Freudian psychoanalytic theory hold that complex operations are performed by the unconscious, but where Freud's theory suggests that the unconscious represses harmful memories to protect one's ego, UTT's version of UT performs rational operations to complete unsolved cognitive or affective tasks.
Probably the most striking contrast UTT has with today's understanding of the unconscious is that between its main claim and studies on implicit perception.
[10] Researchers Ap Dijksterhuis, Maarten W. Bos, Loran F. Nordgren, and Rick B. van Baaren tested this hypothesis in a series of studies measuring choice quality and post-choice satisfaction after participants used conscious and unconscious deliberation.
[10] In light of the difference in capacity between CT and UT, Dijksterhuis used a series of five experiments to test two hypotheses about the decision-making process of unconscious thought.
[11] According to cognitive psychologist George Miller, one cannot hold more than seven items, plus or minus two, in conscious working memory; unconscious thought does not have this restriction.
[11] Given its low capacity, conscious thought must use a "top-down" style of processing that uses shortcuts or schemas to work efficiently.
When asked about the secret behind their brilliant work, Nobel Prize winners and famous artists have often cited incubation, saying that simply understanding the problem they wanted to solve and not paying mind to it somehow procured a solution.
The scientific journal Judgment and Decision Making has published several studies over the years that fail to provide support for the unconscious thought theory.
The earliest meta-analysis of UTT, done by Acker,[15] found no support for the claim that UT is superior to CT in complex decision making.
They concluded 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.
[19][20] It is known that unconscious thought can interpret single words or images, and that deliberating over a simple problem for too long can be disadvantageous.
It remains unclear under what circumstances, if any, it is best to delegate decision problems to one's unconscious by diverting attention from them (see Payne,[18] Waroquier[19] and Srinivasan & Mukherjee[21]), and to what extent logical, rule-based thought processes can occur outside of awareness.