Can human irrationality be experimentally demonstrated?

Abstract

The object of this paper is to show why recent research in the psychology of deductive and probabilistic reasoning does not have "bleak implications for human rationality," as has sometimes been supposed. The presence of fallacies in reasoning is evaluated by referring to normative criteria which ultimately derive their own credentials from a systematisation of the intuitions that agree with them. These normative criteria cannot be taken, as some have suggested, to constitute a part of natural science, nor can they be established by metamathematical proof. Since a theory of competence has to predict the very same intuitions, it must ascribe rationality to ordinary people.Accordingly, psychological research on this topic falls into four categories. In the first, experimenters investigate conditions under which their subjects suffer from genuine cognitive illusions. The search for explanations of such performance errors may then generate hypotheses about the ways in which the relevant information-processing mechanisms operate. In the second category, experimenters investigate circumstances in which their subjects exhibit mathematical or scientific ignorance: these are tests of the subjects' intelligence or education. In the third and fourth categories, experimenters impute a fallacy where none exists, either because they are applying the relevant normative criteria in an inappropriate way or because the normative criteria being applied are not the appropriate ones.

Belief polarization is not always irrational.

“…It is therefore natural to wonder whether irrational behavior can ever be definitively identified (Cohen, 1981). The primary goal of this article was to show that some apparently questionable inferences may be rational after all, but the same normative approach can be used to identify irrational behavior.…”

The intersection between Descriptivism and Meliorism in reasoning research: further proposals in support of ‘soft normativism’

“…The external validity problem, which is closely allied with Cohen’s (1981) argument noted above, is that the tasks that researchers select in order to demonstrate human irrationality are not at all representative of the tasks that arise in real-world contexts, which tend to be associated with normatively accurate reasoning. Evans (2007) argues that the interpretation problem and the external validity do not hold up to close scrutiny because they fail to offer ‘complete’ accounts of the discrepancy between normative benchmarks and actual behavior.…”

Argumentation and education: notes for a debate / Argumentación y educación: apuntes para un debate

“…This point of view contrasts with results found in educational contexts where clear difficulties are shown in the teaching and learning of argumentation, as well as in the analysis of reasoning. We will not enter into discussions concerning logicism within the field of psychology at this time (for example, see Cohen, 1981). We only wish to stress that the experimental results indicated that the biases, fallacies and limitations in the form of producing, understanding or solving problems with logical structures were more common than the use of the norms.…”