Thursday, November 17, 2011

More on Motivated Reasoning

Mercier and Sperber give an impressive argument here:  Why Do Humans Reason?  Arguments for an argumentative theory  The standard view of reasoning is that its primary function is correct cognitive functions and find the truth.  They argue that it is better understood as facilitating persuasion in social or communication contexts.  Their thesis, they maintain, better explains the available evidence that shows how bad humans are at reasoning.

Their section on Motivated Reasoning contains this nice summary of some of the literature.  The applications to the sorts of reasoning we frequently see coming from religious believers seeking to defend the God/Jesus conclusion at all costs are striking.  For now, all I have time to do is offer a long quote:

A series of experiments by Ditto and his colleagues, involving reasoning in the context of a fake medical result, illustrate the notion of motivated reasoning (Ditto & Lopez 1992; Ditto et al. 1998; 2003). Participants had to put some saliva on a strip of paper and were told that, if the strip changed color or did not change color, depending on the condition, this would be an indication of an unhealthy enzyme deficiency.  Participants, being motivated to believe they were healthy, tried to garner arguments for this belief. In one version of the experiment, participants were told the rate of false positives, which varied across conditions. The use they made of this information reflects motivated reasoning. When the rate of false positives was high, participants who were motivated to reject the conclusion used it to undermine the validity of the test. This same high rate of false positives was discounted by participants who were motivated to accept the conclusion. In another version of the experiment participants were asked to mention events in their medical history that could have affected the results of the test, which gave them an opportunity to discount these results. Participants motivated to reject the conclusion listed more such events, and the number of events listed was negatively correlated with the evaluation of the test. In these experiments, the very fact that the participant’s health is being tested indicates that it cannot be taken for granted. The reliability of the test itself is being discussed. This experiment, and many others to be reviewed in this article, demonstrate also that motivated reasoning is not mere wishful thinking (a form of thinking that, if it were common, would in any case be quite deleterious to fitness and would not be coherent with the present theory). If desires did directly affect beliefs in this way, then participants would simply ignore or dismiss the test. Instead, what they do is look for evidence and arguments to show that they are healthy or at least for reasons to question the value of the test.

Other studies have demonstrated the use of motivated reasoning to support various beliefs that others might challenge. Participants dig in and occasionally alter their memories to preserve a positive view of themselves (Dunning et al. 1989; Ross et al. 1981; Sanitioso et al. 1990). They modify their causal theories to defend some favored belief (Kunda 1987). When they are told the outcome of a game on which they had made a bet, they use events in the game to explain why they should have won when they lost (Gilovich 1983). Political experts use similar strategies to explain away their failed predictions and bolster their theories (Tetlock 1998). Reviewers fall prey to motivated reasoning and look for flaws in a paper in order to justify its rejection when they don’t agree with its conclusions (Koehler 1993; Mahoney 1977). In economic settings, people use information flexibly so as to be able to justify their preferred conclusions or arrive at the decision they favor (Boiney et al. 1997; Hsee 1995; 1996a; Schweitzer & Hsee 2002).

All these experiments demonstrate that people sometimes look for reasons to justify an opinion they are eager to uphold. From an argumentative perspective, they do this not to convince themselves of the truth of their opinion but to be ready to meet the challenges of others. If they find themselves unprepared to meet such challenges, they may become reluctant to express an opinion they are unable to defend and less favorable to the opinion itself, but this is an indirect individual effect of an effort that is aimed at others. In a classical framework, where reasoning is seen as geared to  achieving epistemic benefits, the fact that it may be used to justify an opinion already held is hard to explain, especially since, as we will now show, motivated reasoning can have dire epistemic consequences.


JSA said...

As always, Robin Hanson has key insights.

Leo said...

I would recommend this excelent video about this topic:

Joseph said...

Perhaps we behave that way in order not to succumb to every con artists that exist on this planet.

Sabio Lantz said...

The guts of the gods are made by such reasoning. Dissecting our gods
may help us see through our own games.

The Fog Horn said...

Please take the time to examnine my theory and let others know about it too. Thanks.