Home > Biology, Brain > Reading a paper on evolutionary psychology

Reading a paper on evolutionary psychology

Having not much to do at work yesterday, and not having an internet connection, I started reading this paper on evolutionary psychology, that I had stored sometime back on my phone. It is an interesting and informative paper, which I intend to read again (I normally need 2-3 readings of a paper to really understand it), but there was one point in the paper where it stuck me that the authors were probably attacking a straw man. But first, we will see what is evolutionary psychology.

We are all products of evolution and have no problem in believing that our hands, eyes, ears were all sculpted by Natural Selection. So, when someone asks why we evolved eyes, we dont hesitate to say that we have eyes because it helps us find predators, so we can run away from them, find food to eat, find mates to mate and so on. But we hesitate to think that our behaviour too could be a result of evolution. Or at least, we dont attribute evolutionary purposes to our behaviour as readily as we assign such purpose to parts of our physical body. Evolutionary psychology addresses this gap. It studies our behaviour, psychology, by looking at what pressures in our ancient past would have driven us to the way we behave today. The problem today with evolutionary psychology, it appears, is that many scientists are putting forward theories that are not really testable, or at least not have been tested. Read this post from Jerry Coyne to get an idea of the issue.

Now coming back to that paper I referred to in the first sentence. It is a good paper that covers the issues in evolutionary psychology and explains them clearly, but the following question posed stood out for me.

Don’t people just solve problems using rationality? Wouldn’t one domain-general rationality mechanism be more parsimonious than postulating many domain-specific mechanisms?

In human readable English, the question means this. Dont people always use their brains and rationally think about the consequences when faced with a particular question in hand and then behave in a manner best for them? Or are there circuits in our brain that are specific to the situations we are in, which means we react immediately without any logical thought process? The authors point this out and give the following example to explain why domain general rationality does not seem to be how our brains behave.

Domain-general theories of rationality imply a deliberate calculation of ends and a sample space of means to achieve those ends. Performing the computations needed to sift through that sample space requires more time than is available for solving many adaptive problems, which must be solved in real time. Consider a man coming home from work early and discovering his wife in bed with another man. This circumstance typically leads to immediate jealousy, rage, violence, and sometimes murder (Buss, 2000; Daly & Wilson, 1988). Are men pausing to rationally deliberate over whether this act jeopardizes their paternity in future offspring and ultimate reproductive fitness, and then becoming enraged as a consequenceof this rational deliberation? The predictability and rapidity of men’s jealousy in response to cues of threats to paternity points to a specialized psychological circuit rather than a response caused by deliberative domain-general rational thought. Dedicated psychological adaptations, because they are activated in response to cues to their corresponding adaptive problems, operate more efficiently and effectively for many adaptive problems. A domain-general mechanism “must evaluate all alternatives it can define. Permutations being what they are, alternatives increase exponentially as the problem complexity increases” (Cosmides & Tooby, 1994, p. 94). Consequently, combinatorial explosion paralyzes a truly domain-general mechanism (Frankenhuis & Ploeger, 2007).

I have written an article earlier on the gene’s eye view for the New Indian Express on how it is because there is a genetic advantage in loving children that we ended up being so nice to our progeny and ended it with the following paragraph.

This does not mean that every time parents tend for children, they do calculations in their heads, or that they do it for selfish reasons without genuine love. It only means that evolution has come up with emotions like love and empathy as a mechanism for the genes to achieve their goals.

So I never thought that we were always doing a rational analysis of the situation before we react to something. Our brains definitely seem to be wired for some quick reactions (imagine your son who is about to fall down and hurt himself seriously. Would you calculate how much of your genes he has got before trying to save him?) We obviously have some context specific wirings in our head. So it is hard to see why anyone would believe in such patently wrong ideas. I, obviously, do not know the history of this field and there might have been people who have argued that way, but today it seems to be impossible that there could be people who support this theory.

Assuming some one does believe in domain general rationality (assuming the straw man is not just a straw man but a real person), the author’s point of there existing too many permutations for us (men) to evaluate and to react, when we see our spouse in bed with another man, though correct, is a round about way of countering the argument. An easier way to argue against domain general rationality is that if that were true, then this man who sees his bed in wife with another man though initially gets jealous and angry (because, if his wife becomes pregnant now, he cannot be sure if he is the father) must immediately calm down if he sees that this other man was wearing a condom (which means he couldnt have impregnated his wife). I am sure those supporters of the rationality theory will also agree that this scenario will never happen? So, what are they supporting then?

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  1. April 25, 2013 at 23:16

    I believe that both general rationality and specific mechanistic process are parts of human thinking. But which will dominate in a particular situation and in a particular person depends on many things that even any kind of psychology could really explain as of today. In order to get more clear understanding on these things , we have to still understand how complex interactions ( in our billions of neurons in the brain) will finally “emerge” into a coherent specific behavior. In a nut shell, we have to understand and predict the results of non linear chaotic behavior systems !!!

    • April 26, 2013 at 07:33

      I agree that it is a combination of both (I dont deny that in the post), but to counter the argument that all we do is because of a general rationality of our brains, one example where that is obviously not the case is good enough. And that is what I have tried to do.

      • April 26, 2013 at 20:15

        ok…

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