It is unfair in discussion when a man makes no distinction between merely trying to make points and carrying on a real argument. – Socrates
Sorry, Socrates, but now two researchers are reversing the usual way of looking at flawed reasoning. In their view, the flaws are not only not flaws — they’re the main purpose of reasoning itself.
Much has been written about the weaknesses of reasoning. In particular, studies of “confirmation bias” have cast doubt on our capacity for objectivity and our ability to discern truth from falsehood.
Typically, confirmation bias and other ways we sift information are seen as misfirings of cognition that interfere with the evolved purpose of reasoning, which is to seek and recognize what’s true.
Hugo Mercier and Dan Sperber propose an “argumentative theory” of reasoning. In this view, reasoning is an adaptation selected for its utility in winning arguments, not discovering truth. Reasoning is not the supreme mental function; rather, it is applied to intuitive beliefs after those beliefs have been intuitively generated. In this view, we spontaneously adopt beliefs, then reflectively find ways to justify them.
In “Why do humans reason? Arguments for an argumentative theory,” published in the journal Behavioral and Brain Sciences, Mercier and Sperber ask a key evolutionary question: If confirmation bias and other flaws in reasoning are really flaws, why haven’t they been selected out by now? Put another way, if we have a universal (i.e., hard-wired) tendency to certain reasoning flaws, could it be that those “flaws” are really misunderstood positive adaptations? Could they serve some useful purpose, which would explain why they persist?
Mercier and Sperber’s answer is that “the function of reasoning is argumentative. … Reasoning so conceived is adaptive given the exceptional dependence of humans on communication and their vulnerability to misinformation.”
Reasoning so motivated can distort evaluations and attitudes and allow erroneous beliefs to persist. Proactively used reasoning also favors decisions that are easy to justify but not necessarily better. In all these instances traditionally described as failures or flaws, reasoning does exactly what can be expected of an argumentative device: Look for arguments that support a given conclusion.
Making much of the wealth of recent research showing that our mental processes are mostly intuitive, and therefore unconscious, Mercier and Sperber argue that reasoning is the sum of the interaction of a number of pre-existing cognitive events, rather than a single and dedicated “logic circuit”:
An evolutionary approach suggests that inferential processes, rather than being based on a single inferential mechanism or constituting a single integrated system, are much more likely to be performed by a variety of domain-specific mechanisms, each attuned to the specific demands and affordances of its domain.
They go one step further, claiming that there is another inferential and intuitive mechanism that is “metarepresentational.” That is, it allows us to represent representations of arguments and to select, unconsciously, those arguments which will be most convincing to those others whom we are trying to convince.
Mercier and Sperber do not claim that argument is the only positive function of reasoning, only that argument is reasoning’s primary function:
We are not arguing against the view that our reasoning ability may have various advantageous effects, each of which may have contributed to its selection as an important capacity of the human mind. We do argue, however, that reasoning is best adapted for its role in argumentation.
One of the objections raised to the argumentative theory of reasoning is that argument, which depends on language, is a late arrival in evolutionary terms. To explain reasoning as an adaptation to support argument doesn’t explain reasoning’s function before the development of language, nor why reasoning operates in nonverbal or language-free areas, in circumstances for which we don’t have words.
Mercier and Sperber anticipate objections, especially the concern that their theory may be merely another “just so” story. They counter this objection with a series of predictions. If the available experimental evidence can be explained best by their theory, they argue, they will have gone a long way to demonstrating its merit.
Several predictions can be derived from the argumentative theory of reasoning. The first and most straightforward is that reasoning should do well what it evolved to do; that is, produce and evaluate arguments.
Reasoning used to produce argument should exhibit a strong confirmation bias.
When people reason on their own about one of their opinions, they are likely to do so proactively, that is, anticipating a dialogic context, and mostly to find arguments that support their opinion.
Even in decision making, the main function of reasoning is to produce arguments to convince others.
Reasoning will drive people towards decisions for which they can argue – decisions that they can justify – even if these decisions are not optimal.
The bulk of Mercier and Sperber’s long paper goes painstakingly through the published research, showing how, in their view, argumentative theory best explains results that, interpreted traditionally, have been inconclusive or contradictory.
A detailed summary of their analysis is beyond the scope of this article, but if you want to read all of it, just follow the article link above. And if you’re really interested in this subject, there is a related article by Mercier and Helene E. Landemore, “Reasoning is for Arguing: Understanding the Successes and Failures of Deliberation,” available here.
In their study’s conclusions, Mercier and Sperber reiterate their main points: “Reasoning contributes to the effectiveness and reliability of communication by enabling communicators to argue for their claim and by enabling addressees to assess these arguments. It thus increases both in quantity and in epistemic quality the information humans are able to share.”
In their view, “the evolution of reasoning [is] linked to that of human communication. … Thanks to reasoning, human communication is made more reliable and more potent.”
While most of their conclusions can be derived from other theories, “We would argue, however, that the argumentative hypothesis provides a more principled explanation of the empirical evidence (in the case of the confirmation bias, for instance).”
Using their theory:
Reasoning can lead to poor outcomes not because humans are bad at it but because they systematically look for arguments to justify their beliefs or their actions. The argumentative theory, however, puts such well-known demonstrations of “irrationality” in a novel perspective. Human reasoning is not a profoundly flawed general mechanism; it is a remarkably efficient specialized device adapted to a certain type of social and cognitive interaction at which it excels.
But surely there have been great successes, especially in the sciences and in technology, from reasoning? Of course, Mercier and Sperber admit. But they explain this success in terms of confirmation bias and group communication, often over many generations:
When one happens to be on the right track and “more right” than one could initially have guessed, some of the distorting effects of motivated reasoning and polarization may turn into blessings. For instance, motivated reasoning may have pushed Darwin to focus obsessively on the idea of natural selection and explore all possible supporting arguments and consequences. But, for one Darwin, how many Paleys?
An argumentative theory of reasoning is both clever and intriguing, but I’m more with the critics than the authors. We were assessing and responding to environmental stimuli long before we were talking to others, much less holding town hall meetings.
While some features of our cognitive processes lead to both argument and mistaken beliefs, I’m not at all convinced that it works the other way around.
Now excuse me, but I have to go — I need to look up some confirmatory arguments for my last statement.