Component probabilities and the conjunction fallacy: Resolving signed summation and the low component model in a contingent approach

doi:10.1016/0001-6918(95)00048-8

Acta Psychologica

Volume 94, Issue 1, October 1996, Pages 1-20

https://doi.org/10.1016/0001-6918(95)00048-8 Get rights and content

Abstract

This study investigates the conflicting implications of the low component and signed summation explanations for the conjunction fallacy. Error data across three different conjunction types replicate the pattern found by Yates and Carlson (1986), but the results also reveal, consistent with the predictions of the low component model, that for conjunctions of an unlikely event with a likely event (LU) the unlikely component is given disproportionate weight by subjects. However, this result did not generalise to conjunctions of an unlikely with an unlikely event (UU), nor to those involving a likely with a likely (LL). The combined results show the conjunction fallacy is highly sensitive to task characteristics, and suggests the need for a more contingent explanation of the phenomenon. We argue that the low component model and signed summation are both compatible within a process-based explanation that distinguishes between problem structuring and conjunction evaluation.

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Citation Excerpt :
A second possibility is that generally better qualified individuals acquired some form of reasoning or critical thinking ability - perhaps improved verbatim matching/monitoring or better task mindfulness (cf. Liberali, Reyna, Furlan, Stein, & Pardo, 2012) - that is more suited to judging conjunctive outcomes than statistical training alone. A third is that, by virtue of their broader education and university experiences, those with higher general qualifications were, for some as yet unknown reason, less surprised by the subjectively less likely (LL) constituent event which, as noted earlier, is key to shaping conjunctive probabilities estimates and potential CE generation (Fisk, 2002; Fisk & Pidgeon, 1996). Subsequent testing in which all LL × qualification correlations were significant and of similar magnitude except for LL × math/statistics/psychology-specific qualifications given related constituents (causal conjunctions) offers some support for this suggestion.9
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Component probabilities and the conjunction fallacy: Resolving signed summation and the low component model in a contingent approach

Abstract

Organizational Behavior and Human Decision Processes

Organization Behaviour and Human Decision Processes

Distributional and non-distributional uncertainty

Heuristic and analytic processes in reasoning

British Journal of Psychology

Bias in human reasoning: Causes and consequences

Information processing heuristics in probabilistic reasoning

How to make cognitive illusions disappear: Beyond “heuristics and biases”

Probabilistic mental models: A Brunswikian Theory of Confidence

Psychological Review