Irrationality Re-Examined: A Few Comments on the Conjunction Fallacy

Abstract

In this paper, I argue that the probability model used to infer irrationality for the subjects in the famous Linda problem is not appropriate, and I suggest different approaches based on fuzzy reasoning models. My line of argument is two-fold: 1) If the term “probability” is understood properly (mathematically), then the experimenters used the wrong model. 2) If the term “probability” is understood casually (non- mathematically), then alternative models perhaps should be used to justify the subjects’ responses. The objective is to experiment with new ways of looking at irrationality and raise a discussion regarding the relation between irrationality, reasoning errors and logical models that are used as frameworks to study irrationality.

In this paper, I argue that the probability model used to infer irrationality for the subjects in the famous Linda problem is not appropriate, and I suggest different approaches based on fuzzy reasoning models. My line of argument is two-fold: 1) If the term “probability” is understood properly (mathematically), then the experimenters used the wrong model. 2) If the term “probability” is understood casually (non- mathematically), then alternative models perhaps should be used to justify the subjects’ responses. The objective is to experiment with new ways of looking at irrationality and raise a discussion regarding the relation between irrationality, reasoning errors and logical models that are used as frameworks to study irrationality.