About Linda Again: How Narratives and Group Reasoning Can Influence Conjunction Fallacy

Abstract

Conjunction fallacy (together with other systematic reasoning errors) is usually explained in terms of the dual process theory of reasoning: Biases should be ascribed to fast and automatic processes, whereas slow and deliberative processes are responsible of producing answers that are correct with respect of normative criterion. The dual process theory is related to Bruner’s distinction between narrative and paradigmatic thought: Both modes of thought can be characterized by the two different processes of reasoning. In this paper, we explore the role of Bruner’s mode of thought manipulating also the difference between group vs individual reasoning. We observed that the narrative strategy of response induces more wrong answers. However, narrative-based strategies have higher effectiveness in the case of group reasoning. Our results suggest that narrative reasoning and group reasoning may induce violations of the conjunction rule when acceptable by the verisimilitude of the story. Five models are also presented in order to predict answer correctness and strategy of reasoning using a text analysis software.

How general is the natural frequency effect? The case of joint probabilities

“…Besides the original study of the Linda problem by Tversky and Kahneman (1983) , many studies document that people consider the second option with two events at the same time as more likely as the first option with only one event (e.g., Charness et al, 2009 ; Donati et al, 2019 ). However, as demonstrated above, one single event is always more probable than the simultaneous occurrence of this event and an additional event.…”

“…There is an interesting tension in empirical research on the understanding of joint probabilities (formal: e.g., P(A∩B)). On one hand, researchers have stressed the importance of comprehending joint probabilities, e.g., in the legal context ( O’Grady, 2023 ) and conducted empirical studies (e.g., Tversky and Kahneman, 1974 ; Donati et al, 2019 ). On the other hand, psychological studies mostly just ask for a qualitative comparison of P(A) and P(A∩B) without the need for participants to assess a concrete joint probability.…”