Just how irrational are we? Very?

Very, or potentially very irrational, defining "irrational" and "rational" in terms of the great project of Descartes and followers, it seems.

In a blog post at Discover, in follow-up to his column last week at Mother Jones, Chris Mooney notes that the journal Behavioral and Brain Sciences has devoted an entire issue to what he covered at Mojo, with links to summaries of key content.

Here's a couple of key outtakes:

First:

Reasoning is generally seen as a means to improve knowledge and make better decisions. However, much evidence shows that reasoning often leads to epistemic distortions and poor decisions. This suggests that the function of reasoning should be rethought. Our hypothesis is that the function of reasoning is argumentative. It is to devise and evaluate arguments intended to persuade. Reasoning so conceived is adaptive given the exceptional dependence of humans on communication and their vulnerability to misinformation. A wide range of evidence in the psychology of reasoning and decision making can be reinterpreted and better explained in the light of this hypothesis. Poor performance in standard reasoning tasks is explained by the lack of argumentative context. When the same problems are placed in a proper argumentative setting, people turn out to be skilled arguers. Skilled arguers, however, are not after the truth but after arguments supporting their views. This explains the notorious confirmation bias. This bias is apparent not only when people are actually arguing, but also when they are reasoning proactively from the perspective of having to defend their opinions.

And more, from a response to some of the issues:

When people reason alone, there will often be nothing to hold their confirmation bias in check. This might lead to distortions of their beliefs. As mentioned above, this is very much the case. When people reason alone, they are prone to all sorts of biases.

In short, as Mooney notes, classical Cartesianism appears m ore and more dead in the water. First, Dan Dennett (and others) said there is no little man, no Cartesian homunculus, making magic rationality decisions inside us.

Now, BBS et al say that, even if there were such a critter, he wouldn't be a disinterested rationalist anyway.

But, not all commenters on Mooney's post want to accept that, it seems.

I responded to one:

Nullius, (you seem to present) a great defense of the “traditional” view of reasoning or whatever …

BUT, I’m going to argue with you.

First, the “reasoning as argumentation” model I think explicitly says this is NOT, NOT, NOT, a “human failing.” Rather, it is, if I may, “human ISness.”

I won’t propose abandoning “rationalism,” but I will say that it is even more unnatural than you may want to admit.

And, that IS a conflict with Cartesianism, which postulates rationality is a cornerstone of homo sapiens.

Sorry, but, either you don’t get the degree of implications this involves, or …
You DO, unconsciously, understand precisely what is up and by your conscious argumentation, actually support the fact at hand.

Of course, maybe I have reasons for my argumentation.

Meanwhile, this SciAm blog explains some of the reasons for our irrationality, in terms of motivators.