A formal theory can explain disjunctive illusory inferences.

Miguel López Astorga

doi:10.5209/rev_clac.2014.v60.47445

Miguel López Astorga

Open Access

https://doi.org/10.5209/rev_clac.2014.v60.47445

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Abstract

There are disjunctive inferences that can be considered to be illusory, since, when faced to them, people tend to draw logically incorrect conclusions. The mental models theory can explain this problem by distinguishing between mental models and fully explicit models. According to it, individuals often derive only conclusions compatible with the mental models, and not with the fully explicit models. However, I try to show in this paper that a syntactic approach can also account for the problem of the mentioned inferences. It is enough to assume that disjunctions are basically inclusive and that exclusive disjunctions require resorting to more complex formulae.

Highlights

There are disjunctive inferences that can be considered to be illusory, since, when faced to them, people tend to draw logically incorrect conclusions
My goal is to show that other alternative type of theories that is explicitly mentioned by Khemlani and Johnson-Laird (2009) in the previous quote, the formal rules theories, can account for the facts related to the disjunctive illusory inferences
As it will be shown below, a syntactic approach can explain both the conclusions that individuals often derive from these inferences and the improvement that the additional instructions used by Khemlani and Johnson-Laird (2009) provide

Summary

The problem of the disjunctive illusory inferences

If the previous example referring to the bread, the soup, and the salad is taken into account, and it is assumed that ‘V’ stands for the logical exclusive disjunction, it can be said that the logical form of its first premise is as follows:. As it is well known, according to standard logic, an exclusive disjunction is true when a disjunct is true and the other disjunct is false. It is possible that, in the example considered, you have the bread, the soup, and the salad at the same time This circumstance can lead one to think that human mind does not follow the requirements of standard logic. The mental models theory gives us such a framework

The mental models theory and disjunctions

The mental models theory and the disjunctive illusory inferences

Disjunctive illusory inferences and the mental logic theory

Conclusions