Making a Decision: Using Conscious vs Unconscious Thinking to Solve the Problem

doctor and nurse looking at x-ray
doctor and nurse looking at x-ray
A physician discusses conscious and unconscious problem solving methods.

Approximately a decade ago, academic circles were set abuzz, as they are wont to do, by a set of studies that had produced some curious findings. The experiments went like this: a group of college students, with nothing better to do and eager to earn a little beer money, were split into 2 groups. Each participant was asked to select the “better” of 2 apartments or automobiles or some other common consumer product. Although one man’s palace can be another’s prison, the studies were designed such that one of the two options would be objectively superior — that way there would always be a right answer. Both groups of students were given the same information to consider before making their decision, although some were given data about a greater number of attributes, so that the researchers could distinguish between simple and complex decision making.

As it turned out, at least in some cases, the students made better decisions — that is, more frequently selected the superior item — if, before making their choice, they were subjected to a period of what is known as deliberation without attention. Basically, if the students were made to solve anagrams or word search puzzles for a few minutes — instead of thinking about the problem that they had been assigned — the quality of their decision making improved. What’s more, the effect seemed to become more pronounced as the complexity of the scenario increased.¹³

This conclusion stands in stark contrast to what (we think) we know about thinking and problem solving. Intuitively, sophisticated problem solving requires deliberately, consciously considering the problem before rendering a conclusion. This wisdom is tied up in the aphorisms that we inculcate in young physicians: “Think before you act”; “Don’t just do something — stand there”; “Haste makes mistakes.” Still, doctors immediately took note, and rightfully so. We are constantly making complex decisions under conditions of risk and uncertainty — and, in our world, the consequences of a bad decision are a lot more severe than getting stuck with a car that’s a lemon for a few years. If we could improve decisions simply by replacing conscious deliberation with a brief period of distraction, it would represent a great — and essentially costless — step forward for us, and for our patients.

Alas, when things appear too good to be true, they usually are. Contrary to our hopes and dreams, the value of deliberation without attention has failed to be validated in anything resembling a clinical environment. In fact, substantial questions have since been raised about the existence of this effect in any context. A comprehensive meta-analysis, for instance, found that although a number of the supporting studies did demonstrate an effect in the hypothesized direction, they also very often failed to reach the level of statistical significance. That same meta-analysis also concluded that conscious thinkers were more successful at both identifying the top choice and distinguishing between more mediocre options.4 Studies that have focused exclusively on clinical context have come to similar conclusions. The takeaway is that there is no reason to believe that practicing physicians would benefit from distracting themselves with irrelevant tasks before making patient-centered decision.5 Too bad. I guess I shouldn’t have rushed out and bought that enormous book of word search puzzles. 

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When I was going over these studies, one particular finding jumped out at me. In one experiment, the participants were divided into expert and novice groups, and each group was given either simple or complex medical problems to solve. As I am sure you guessed, deliberation without attention was mostly found to be useless, but there was at least one exception: when novice doctors (medical students, actually) tackled simple problems. It seemed that, compared with making an immediate judgment, taking a few minutes to complete some irrelevant mental exercise improved their outcomes substantially.6

There is not much other literature corroborating this finding in a clinical context, so it is entirely possible that I am being led down the garden path by the streetlight effect, confirmation bias, or some other nefarious impediment to clear thinking. However, I think that this result makes good sense and says something about the how we teach young doctors to think. The unifying characteristic of young physicians — including and especially medical students — is that their fund of knowledge is poorly developed. They simply do not know as much about medicine and clinical decision making as experts do. That helps explain why unconscious deliberation is useful to them for simple problems but not for complex ones. The complex scenarios are likely to require information that the novice does not have, and will not be able to summon, no matter how long he or she spends trying. If that logic is correct — and ultimately verified by the scientific method — then we would do well to consider incorporating systematic non-attentive deliberation pauses into the process of effectuating the relatively simple decisions that we entrust to junior physicians.

More important though is what this study suggests about the various modern initiatives, such as night float regulations and the 80-hour work week, that have sought to draw a bright line between work and personal time. These ideas are rooted in our contemporary understanding of the importance of self-care as well as an acknowledgment that lifestyle considerations can very often dissuade talented people from pursuing demanding specialties. Yet, many smart practitioners bemoan the potential of these regulations, however well intentioned, to both damage the doctor-patient bond and diminish the extent to which any given physician feels responsible for his or her patient’s care. The notion that deliberation without attention might be valuable — even under limited circumstances — only serves to ratchet up that tension. The true value of the study, at least as far as I can tell, is as a reminder that, for their sake, we should always be thinking about our patients, even when we are not —which, come to think of it, is really just another way of re-stating the arguments against duty hour limits. These viewpoints might be impossible to reconcile, and I am not exactly sure how we determine the best path forward. I do have an idea, though. Why don’t we all take some time and sleep on it?


  1. Dijksterhuis A, Bos MW, Nordgren LF, van Baaren RB. On making the right choice: the deliberation-without-attention effect. Science. 2006; 311(5763):1005-1007.
  2. Dijksterhuis A, Meurs T. Where creativity resides: The generative power of unconscious thought. Conscious Cogn. 2006;15(1):135-146.
  3. Dijksterhuis A. Think different: the merits of unconscious thought in preference development and decision making. J Pers Soc Psychol. 2004:87(5):586-598.
  4. Acker, F. New findings on unconscious versus conscious thought in decision making: additional empirical data and meta-analysis. Judgment and Decision Making. 2008;3(4):292-303.
  5. Bonke B, Zietse R, Norman G, et al. Conscious versus unconscious thinking in the medical domain: the deliberation-without-attention effect examined. Perspect Med Educ. 2014;3(3):179-189.
  6. Mamede S, Schmidt HG, Rikers RM, Custers EJ, Splinter TA, van Saase JL. Conscious thought beats deliberation without attention in diagnostic decision-making: at least when you are an expert. Psychol Res. 2010;74(6):586-592.