The psychology of reasoning (also known as the cognitive science of reasoningOaksford, M., & Chater, N. (2002). Commonsense reasoning, logic, and human rationality. In R. Elio (Ed.), Common Sense, Reasoning, and Rationality (pp. 174–214). Oxford University Press) is the study of how people reason, often broadly defined as the process of drawing conclusions to inform how people solve problems and make decisions.Leighton, J. P. (2004). Defining and describing reason, in The Nature of Reasoning (eds Leighton, J. P. and Sternberg, R. J.) Cambridge University Press. It overlaps with psychology, philosophy, linguistics, cognitive science, artificial intelligence, logic, and probability theory.
Psychological experiments on how humans and other animals reason have been carried out for over 100 years. An enduring question is whether or not people have the capacity to be rational. Current research in this area addresses various questions about reasoning, rationality, judgments, intelligence, relationships between emotion and reasoning, and development.
Everyday reasoning One of the most obvious areas in which people employ reasoning is with sentences in everyday language. Most experimentation on deduction has been carried out on hypothetical thought, in particular, examining how people reason about conditionals, e.g., If A then B.Evans, J.St.B.T., Newstead, S. and Byrne, R.M.J. (1993). Human Reasoning: The Psychology of Deduction. Hove, UK, Psychology Press. Participants in experiments make the modus ponens inference, given the indicative conditional If A then B, and given the premise A, they conclude B. However, given the indicative conditional and the minor premise for the modus tollens inference, not-B, about half of the participants in experiments conclude not-A and the remainder concludes that nothing follows.
The ease with which people make conditional inferences is affected by context, as demonstrated in the well-known selection task developed by Peter Wason. Participants are better able to test a conditional in an ecologically relevant context, e.g., if the envelope is sealed then it must have a 50 cent stamp on it compared to one that contains symbolic content, e.g., if the letter is a vowel then the number is even. Background knowledge can also lead to the suppression of even the simple modus ponens inference Byrne, R.M.J. (1989). Suppressing valid inferences with conditionals. Cognition, 31, 61–83. Participants given the conditional if Lisa has an essay to write then she studies late in the library and the premise Lisa has an essay to write make the modus ponens inference 'she studies late in the library', but the inference is suppressed when they are also given a second conditional if the library stays open then she studies late in the library. Interpretations of the suppression effect are controversial
Other investigations of propositional inference examine how people think about disjunctive alternatives, e.g., A or else B, and how they reason about negation, e.g., It is not the case that A and B. Many experiments have been carried out to examine how people make relational inferences, including comparisons, e.g., A is better than B. Such investigations also concern spatial inferences, e.g. A is in front of B and temporal inferences, e.g. A occurs before B.Johnson-Laird, P.N. and Byrne, R.M.J. (1991). Deduction. Hillsdale: Erlbaum. Other common tasks include categorical syllogisms, used to examine how people reason about quantifiers such as All or Some, e.g., Some of the A are not B.Johnson-Laird, P.N. (2006). How We Reason. Oxford: Oxford University Press. For example if all A are B and some B are C, what (if anything) follows?
Theories of reasoning There are several alternative theories of the cognitive processes that human reasoning is based on.Byrne, R.M.J. and Johnson-Laird, P.N. (2009).'If' and the problems of conditional reasoning. Trends in Cognitive Sciences, 13, 282–287. One view is that people rely on a mental logic consisting of formal (abstract or syntactic) inference rules similar to those developed by logicians in the propositional calculus.O'Brien, D. (2009). Human reasoning includes a mental logic. Behav. Brain Sci. 32, 96–97. Another view is that people rely on domain-specific or content-sensitive rules of inference.Cosmides, L. et al. (2005) Detecting cheaters. Trends in Cognitive Sciences. 9, 505–506. A third view is that people rely on mental models, that is, mental representations that correspond to imagined possibilities.Johnson-Laird, P.N. and Byrne, R.M.J. (2002) Conditionals: a theory of meaning, inference, and pragmatics. Psychol. Rev. 109, 646–678. A fourth view is that people compute probabilities.Oaksford, Mike and Chater, Nick (2007) Bayesian Rationality: The Probabilistic Approach to Human Reasoning. Oxford University Press.
One controversial theoretical issue is the identification of an appropriate competence model, or a standard against which to compare human reasoning. Initially classical logic was chosen as a competence model.See, e.g., Wason, P. C. (1966). "Reasoning", in Foss, B. M.: New Horizons in Psychology. Harmondsworth: Penguin. Subsequently, some researchers opted for non-monotonic logicDa Silva Neves, R., Bonnefon, J. F., & Raufaste, É. (2002). An empirical test for patterns of nonmonotonic inference. Annals of Mathematics and Artificial Intelligence, 34, 107–130. and Bayesian probability. Research on mental models and reasoning has led to the suggestion that people are rational in principle but err in practice. Connectionist approaches towards reasoning have also been proposed.Sun, R. (1994). Integrating Rules and Connectionism for Robust Commonsense Reasoning. John Wiley and Sons, New York. Despite the ongoing debate about the cognitive processes involved in human reasoning, recent research has shown that multiple approaches can be useful in modeling human thinking. For instance, studies have found that people's reasoning is often influenced by their prior beliefs, which can be modeled using Bayesian probability theory.Jern, A., Chang, K. M. K., & Kemp, C. (2014). Belief polarization is not always irrational. Psychological review, 121(2), 206. Additionally, research on mental models has shown that people tend to reason about problems by constructing multiple mental representations of the situation, which can help them to identify relevant features and make inferences based on their understanding of the problem. Moreover, connectionist approaches to reasoning have also gained attention, which focus on the neural network models that can learn from data and generalize to new situations.
Development of reasoning It is an active question in psychology how, why, and when the ability to reason develops from infancy to adulthood.For example: Jean Piaget's theory of cognitive developmentDemetriou, A. (1998). Cognitive development. In A. Demetriou, W. Doise, K. F. M. van Lieshout (Eds.), Life-span Developmental Psychology (pp. 179–269). London: Wiley. posited general mechanisms and stages in the development of reasoning from infancy to adulthood. According to the neo-Piagetian theories of cognitive development, changes in reasoning with development come from increasing working memory capacity, increasing speed of processing, and enhanced executive functions and control. Increasing self-awareness is also an important factor.Demetriou, A., Mouyi, A., & Spanoudis, G. (2010). "The development of mental processing", and Nesselroade, J. R. (2010). "Methods in the study of life-span human development: Issues and answers". In W. F. Overton (Ed.), Biology, Cognition and Methods Across the Life-span. Volume 1 of The Handbook of Life-span Development (pp. 306–345 and 36–55), Editor-in-chief: R. M. Lerner. Hoboken, NJ: Wiley.
In their book The Enigma of Reason, the cognitive scientists Hugo Mercier and Dan Sperber put forward an "argumentative" theory of reasoning, claiming that humans evolved to reason primarily to justify our beliefs and actions and to convince others in a social environment.Mercier, Hugo; Sperber, Dan (2017). The Enigma of Reason. Cambridge, MA: Harvard University Press. Key evidence for their theory includes the errors in reasoning that solitary individuals are prone to when their arguments are not criticized, such as logical fallacies, and how groups become much better at performing cognitive reasoning tasks when they communicate with one another and can evaluate each other's arguments. Sperber and Mercier offer one attempt to resolve the apparent paradox that the confirmation bias is so strong despite the function of reasoning naively appearing to be to come to veridical conclusions about the world.
The study of the development of reasoning abilities is an ongoing area of research in psychology, and multiple factors have been proposed to explain how, why, and when reasoning develops from infancy to adulthood. Recent research has suggested that early experiences and social interactions play a critical role in the development of reasoning abilities.Banerjee, R., Watling, D., & Caputi, M. (2011). Peer relations and the understanding of faux pas: Longitudinal evidence for bidirectional associations. Child development, 82(6), 1887-1905. For example, studies have shown that infants as young as six months old can engage in basic logical reasoning, such as reasoning about the relationship between objects and their properties. Furthermore, research has highlighted the importance of parental interaction and cognitive stimulation in the development of children's reasoning abilities. Additionally, studies have suggested that cultural factors, such as educational practices and the emphasis on critical thinking, can also influence the development of reasoning skills across different populations.
Different sorts of reasoning Philip Johnson-Laird trying to taxonomize thought, distinguished between goal-directed thinking and thinking without goal, noting that association was involved in unrelated reading. He argues that goal directed reasoning can be classified based on the problem space involved in a solution, citing Allen Newell and Herbert A. Simon.
Inductive reasoning makes broad generalizations from specific cases or observations. In this process of reasoning, general assertions are made based on past specific pieces of evidence. This kind of reasoning allows the conclusion to be false even if the original statement is true.Reisberg, Daniel. (2013). Cognition: Exploring the Science of the Mind. W. W. Norton & Company. For example, if one observes a college athlete, one makes predictions and assumptions about other college athletes based on that one observation. Scientists use inductive reasoning to create theories and hypotheses.LiveScience Staff. (2012). Deductive Reasoning vs. Inductive Reasoning. Retrieved from http://www.livescience.com/21569-deduction-vs-induction.html Philip Johnson-Laird distinguished inductive from deductive reasoning, in that the former creates semantic information while the later does not .