Adaptive value of psychological mechanisms

Posted on September 21, 2009


One the BCDC people raised an important issue in the question time after my talk in Bristol. She said that, as a psychologist, she did not ask why certain things were the way they are but was just interested in what they are like. She was talking about the fact that she, like most psychologists, does her work without having to think about the evolutionary processes that led to humans being the way they are. And, indeed, psychology has made a hell of a lot of progress without spending much time worrying about evolutionary history. Yet, of course, it is not longer altogether the case that no psychologists think about evolution – evolutionary psychology being the exception. As I have made clear in previous posts, I am far from complete happy with evolutionary psychology. I do think, though, that by working with some simplistic theoretical assumptions it has managed to make a fair amount of empirical progress in a short period of time. Getting back to the general issue, however, the comment made me think again about how I use evolutionary theory  and how evolution can be useful to psychologists – one of the points that I failed to make strongly enough in my answers. The basic point seems to me to be that when I read various psychological papers I tend to be constantly considering whether the mechanisms they postulate make sense from an evolutionary point of view. Often, I find myself asking what the possible adaptive value of the postulated mechanism is meant to be. Thinking about this strikes me as something that most psychologists would actually find quite useful to consider when doing their work. When they come across a new phenomenon and put forward a theory as to the mechanism behind it, they can immediately ask whether they are dealing with something that is a by-product, is adaptive or is an ancestral trait. Having some idea about which of these they are dealing with will give them ideas as to what they can expect and, very importantly, will at times raise a red flag that the mechanism they postulate is evolutionarily implausible –  I have come across such implausible mechanisms on numerous occasions, unfortunately.

A good example of this last is the work on loss of control that Bruce mentioned during question time but which I also failed to make any intelligent comments about at the time. The problem I have with it, as I have previously mentioned, is that it seems to postulate a mechanism whose function is to make us feel good. Yet, evolution does not care about whether human beings feel good. Indeed pain, discomfort and unease all have the function of motivating animals, including humans, to undertake actions that are likely to increase their chances of survival. If they didn’t feel bad they wouldn’t do what they are for! So, having a mechanism that turns one of these motivating factors off does not generally sound like a good idea from an evolutionary point of view.

The only scenario where it might be a good idea is where the cost of maintaining the response is greater than the likely benefits from future actions motivated by it – a calculation that is hard to make, to say the least. I can imagine that where there is long term loss of control such a mechanism might make sense – spelling out the correct conditions would take a lot of work that has not been done, however. Yet, even in such cases there are alternatives that sound just as, if not more, plausible. The first is that the illusion of control is a means by which apathy is avoided and, thereby, the potential for effective response is maintained – the problem being that sometimes sitting down and waiting without wasting effort is the best response. The second is that illusion of control leads to determined action that, in those few cases where it just happens to be the correct response, is more effective than half-hearted attempts – the problem being that where the response is inappropriate a more gingerly approach may prove less costly. Clearly, I am not saying that either of my proposals are correct, but I am unaware of literature that takes them into account even to merely show that they are incorrect. Yet, it ought to be possible to think of experiments that will tease apart these possibilities.

Posted in: evolution, Psychology