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Friday, August 26, 2022

The Selective Laziness of Reasoning

Trouche, E., Johansson, P., Hall, L., & Mercier, H. 
(2016). Cognitive science, 40(8), 2122–2136.


Reasoning research suggests that people use more stringent criteria when they evaluate others' arguments than when they produce arguments themselves. To demonstrate this "selective laziness," we used a choice blindness manipulation. In two experiments, participants had to produce a series of arguments in response to reasoning problems, and they were then asked to evaluate other people's arguments about the same problems. Unknown to the participants, in one of the trials, they were presented with their own argument as if it was someone else's. Among those participants who accepted the manipulation and thus thought they were evaluating someone else's argument, more than half (56% and 58%) rejected the arguments that were in fact their own. Moreover, participants were more likely to reject their own arguments for invalid than for valid answers. This demonstrates that people are more critical of other people's arguments than of their own, without being overly critical: They are better able to tell valid from invalid arguments when the arguments are someone else's rather than their own.

From the Discussion

These experiments provide a very clear demonstration of the selective laziness of reasoning. When reasoning produces arguments, it mostly produces post-hoc justifications for intuitive answers, and it is not particularly critical of one’s arguments for invalid answers. By contrast, when reasoning evaluates the very same arguments as if they were someone else’s, it proves both critical and discriminating.

The present results are analogous to those observed in the belief bias literature (e.g., Evans et al., 1983). When participants evaluate an argument whose conclusion they agree with, they tend to be neither critical (they accept most arguments) nor discriminating(they are not much more likely to reject invalid than valid arguments). By contrast, when they evaluate argument whose conclusion they disagree with, they tend to be more critical (they reject more arguments) and more discriminating (they are much more likely to reject invalid than valid arguments). The similarity is easily explained by the fact that when reasoning produces arguments for one’s position, it is automatically in a situation in which it agrees with the argument’s conclusion.

Selective laziness can be interpreted in light of the argumentative theory of reasoning (Mercier & Sperber, 2011). This theory hypothesizes that reasoning is best employed in a dialogical context. In such contexts, opening a discussion with a relatively weak argument is often sensible: It saves the trouble of computing the best way to convince a specific audience, and if the argument proves unconvincing, its flaws can be addressed in the back and forth of argumentation. Indeed, the interlocutor typically provides counter-arguments that help the speaker refine her arguments inappropriate ways (for an extended argument, see Mercier, Bonnier, & Trouche, unpublished data). As a result, the laziness of argument production might not be a flaw but an adaptive feature of reasoning. By contrast, people should properly evaluate other people’s arguments, so as not to accept misleading information—hence the selectivity of reasoning’s laziness.

In short: We make better judges for others, and better defense attorneys for ourselves (paraphrasing an old saying).