Psychological dual-process theories contrast analytical reasoning and non-analytical reasoning as two modes of knowing and thinking^1-6.
The analytical system or system 2 is explicit, controlled, rational, effortful and relatively slow. In clinical reasoning, analytical thinking is present in deliberately generating and testing of diagnostic hypotheses, in causal reasoning with biomedical knowledge, and in the use of decision tools. The non-analytical system or system 1 is implicit, based on automatic and effortless thought processes and is associative, intuitive and fast. It can be seen as a process leading rapidly to the selection of the preferred management options for the target condition.^1;7 Non-analytical reasoning can be recognized both in medical decision-making and in medical problem-solving, for instance in automatic chance assessment processes and in pattern recognition. The interaction between these two systems is considered to determine the output of the whole thought process. The outcomes of the non-analytical system can be reflected upon by the analytical system and accepted or elaborated upon for further understanding and investigation or to provide explanations.^1;8;9 Non-analytical, intuitive thinking is explained in terms of the high accessibility of the immediate thoughts.¹⁰

A model of GPs’ diagnostic reasoning visualizes diagnostic reasoning as a mix of analytical and non-analytical reasoning processes, where the three tracks of diagnostic reasoning, medical decision-making, medical problem-solving and gut feelings collaborate within a GP’s knowledge network.¹¹ Depending on the task (routine or more complicated) and the situation (being familiar with a patient and a disease or not) GPs use elements of all three tracks. With increasing experience, their knowledge network will become richer and more coherent and non-analytical reasoning will more often be invoked, but experienced GPs are able to switch to analytical reasoning when the automatic approach is not enough to explain the patient’s situation.

 (1) Kahneman D. A perspective on judgment and choice: mapping bounded rationality. Am Psychol 2003; 58(9):697-720.

(2) Boreham NC. The dangerous practice of thinking. Med Educ 1994; 28(3):172-179.

(3) Ferreira MB, Garcia-Marques L, Sherman SJ, Sherman JW. Automatic and controlled components of judgment and decision making. J Pers Soc Psychol 2006; 91(5):797-813.

(4) Epstein S. Integration of the cognitive and the psychodynamic unconscious. Am Psychol 1994; 49(8):709-724.

(5) Evans JSBT, Frankish K. In Two Minds. Dual processes and beyond. Oxford: Oxford University Press; 2009.

(6) Croskerry P. A universal model of diagnostic reasoning. Acad Med 2009; 84(8):1022-1028.

(7) Eva KW, Hatala RM, Leblanc VR, Brooks LR. Teaching from the clinical reasoning literature: combined reasoning strategies help novice diagnosticians overcome misleading information. Med Educ 2007; 41(12):1152-1158.

(8) National Prescribing Centre (NPC) provided by NICE for the NHS. Making decisions better. MeReC 2011; 22:1-8.

(9) Eva KW, Link CL, Lutfey KE, McKinlay JB. Swapping horses midstream: factors related to physicians’ changing their minds about a diagnosis. Acad Med 2010; 85(7):1112-1117.

(10) Kahneman D, Frederick S. A Model of Heuristic Judgement. In: Holyoak KJ, Morrison R, editors. The Cambridge Handbook of Thinking and Reasoning. New York: Cambridge University Press; 2005. 267-293.

(11) Stolper CF, Van de Wiel M, Van Royen P, Van Bokhoven MA, Van der Weijden T, Dinant GJ. Gut feelings as a third track in general practitioners’ diagnostic reasoning. J Gen Intern Med 2011; 26(2):197-203.