Rational or Irrational, or neither?

[BPSDB] [An edited version of a contribution to the Critical Cafe, supposedly a forum for discussing issues related to Karl Popper’s critical rationalism (in fact, occasionally it is). I was alleged, by another contributor, to believe that people are “irrational”. This person himself, If I understand correctly, holds the position – which underlies much of economic theory – that people are “rational” agents pursuing their own self-interest. This short essay is an attempt to clarify my own position.]

I take ‘rational’ to refer to the use of the best available information (including techniques, reasoning etc.) in achieving an aim, solving a problem or acquiring what one needs or desires. ‘Irrational’ presumably would involve not choosing to do this, and it’s hard to understand why anyone would behave in this way.

One could, of course, rationally act on false information that one believes to be correct, perhaps using a flawed argument, and so come to an unfortunate result.  Many errors are the result of cognitive illusions, such as flawed interpretation of probabilities. These arise from the evolved structure of our minds, applied to situations for which evolution has not prepared us. Rationality would involve the application of techniques to overcome these cognitive errors.

Most of what you and I do is entirely out of our conscious control most of the time. This is highly desirable, because if we had to devote mental capacity to rational debate over every single action, we would be immobilised. There are instinctive actions, for example, ducking to avoid a missile, which we have acquired in our evolutionary history because they enabled our survival. These are neither rational nor irrational.

There are skills we may consciously and no doubt rationally develop, such as walking and the playing of a musical instrument, but the actual actions are neither rational nor irrational. There are also preferences that may have no basis in rationality, for example, my preference for coffee in the morning and tea in the afternoon. (Preferences, can of course, be rational too – if I need to save money and I buy supermarket own-brand items because they are cheaper and do the job as well as the branded alternatives.)

There may well be other categories of actions that could not be classed as either rational or irrational.

So most people are not “irrational”, but rational actions must of necessity be a small (even though very significant) part of our lives. So I think it makes no sense to talk of people, or their behaviour, as being rational or irrational. The only meaningful use of the word ‘rational’ is in relation to specific arguments or actions where the aim or problem is well-defined enough to apply reasoning or relevant information to it.

I can see no validity in asserting that all human behaviour, or a defined part of it (as some economists do) is ‘rational’ in some way. You may assert that a particular conscious action or class of actions, by a particular person or all persons, is rational or irrational (if the latter is possible). But this is a hypothesis, subject to all the limitations of conjectural knowledge as Popper described. And, in general, you will never have the inside knowledge to adequately judge the hypothesis.

The chief executives of both Lehmann Brothers and the Royal Bank of Scotland seem to have had the aim of making their middling institutions into big ones of their kind, and they seem to have found the methods to do that.  Does that make them ‘rational’? Both were apparently warned, using sound arguments, that they were leading to likely disaster, and they ignored or disadvantaged the persons making the warnings. Does that therefore make the CEOs ‘irrational’? It seems to me that it is worthwhile to try to understand the processes that let up to the failures, but would trying to interpret the actions as ‘rational’ or ‘irrational’ add anything to our understanding? I doubt it.

Update 22 July 2009: Heresy Corner, writing about the UK government’s policy on the DNA database, illustrates how this is not merely a philosophical debate. The DNA database policy is founded on an ideological position that criminal behaviour must be a ‘rational’ decision. It also shows that ‘neoliberalism’ is not necessarily about individual freedom from government control.