2 June

Evolution, Causation, and Human Behaviour


Can evolution explain human behaviour? This question has recurred among commentators since the publication of the book Supercooperators: Evolution, Altruism and Human Behaviour or, Why We Need Each Other to Succeed by the Harvard professor, Michael Nowak. The basic idea, as he explains here, is that ‘to succeed in life, you need to work together — pursuing the snuggle for existence, if you like — just as much as you strive to win the struggle for existence’. In evolutionary terms, then, we often gain more by co-operating than by competing.

A notable feature of the (rather contrived) ‘creation-evolution debate’ is the ignorance both sides display of principles of causation established by Aristotle, who noticed that things have four types of causes:

  1. material (what something is made out of);
  2. formal (how its parts are arranged);
  3. efficient (who or what made it what it is);
  4. final (why – that for the sake of which it is).

Take a wooden chair: the material cause is the wood; the formal cause is the plan for the chair the carpenter has in mind; the efficient cause is the carpenter; and the final cause is the man who will sit on the chair.

One side argues that since we know the efficient cause (natural selection), it is unnecessary to posit the existence of a Supreme Being (final cause) who purposefully orders the process (formal cause). The other argues that since we know the final cause (God), there is no need to seek further explanation for the existence of living things.  Effectively, the evolutionist argues: ‘We know the carpenter made the chair, so, as for the idea that chairs are there for people to sit on, this is nothing more than the delusional ravings of tobacco-chewing rednecks clinging to medieval superstition’. The creationist argues: ‘A chair is there for someone to sit on, and so it goes without saying that it was made by the person who sits on it… There is no need to introduce some kind of shadowy ‘carpenter’ figure into the bargain’.

To return to the idea that evolution can furnish us with an explanation for human behaviour, there seems to be a similar confusion about causation in evidence here.

Some scientists, for example, have opined that the northern European tendency towards excessive alcohol consumption derives from a lack of sunlight in their lands. Because our ‘hunter-gatherer ancestors’ were often unable to see approaching danger, they developed heightened anxiety mechanisms, and northern Europeans therefore find it all the more difficult to resist the allure of anxiety-relieving substances such as alcohol.

Supposing this historical reconstruction is true (and there is little to suggest it is more than speculation), it might at most describe one of many material causes which predispose to heavy drinking. To argue, however, that this explains the high levels of alcohol consumption in northern Europe is like arguing that the raw block of wood out of which the chair is made of itself explains why the carpenter made a wooden chair and not a wooden table. In fact, the waters are even muddier when it comes to trying to explain human behaviour, and it is debatable whether we can even attribute material causation to the genetic predispositions we may have inherited via evolutionary processes. After all, it is possible that someone without a genetic predisposition towards alcoholism may end up becoming an alcoholic simply as a result of bad choices, whereas it is not possible to make a wooden chair unless you have the wood to begin with. Either we say that the human will can bring things out of raw material which are not there – which is absurd –, or we observe that every human being has the potential to do every bad act as well as every good act, which is true, but really explains nothing, and so it seems evolutionary biology does not tell us anything beyond the blindingly obvious observation that ‘heredity predisposes us to doing stuff without making us do it’.  What the ‘stuff’ is, or why we do it, is really beyond the reach of biology for, as we have pointed out here recently, the human will is an immaterial faculty beyond the reach of science. This illustrates a certain mystery about humanity: man is composed of body and soul, and therefore his depths cannot be fully sounded by even the most enlightening discoveries of science, which can only tell us about the lower part of man’s nature: the part which has to do with his material body.

One of our hunter-gatherer ancestors hitting the bottle?

Much less – contrary to ideas expressed by some – has evolutionary biology anything to do with morality: a prescriptive affair which tells us what we ought to do and why, not a descriptive science which tells us why we want to do certain things.  To take the ‘supercooperator’ hypothesis as an example, we might ask why it is morally good for us to co-operate. No doubt someone will reply: ‘Because it maximises our chances of surviving long enough to reproduce and rear offspring’. But why are survival and reproduction good things at which we should aim? Here science is silent, for it is of the essence of biology as a discipline that it does not philosophise about ‘life’ as such, but simply studies it given the fact that it already exists. It cannot tell us why life is a good thing that ought to be preserved, or why it is good that humans should procreate. Material science can be useful in telling us which means to avoid if we want to attain certain ends (e.g., ‘If you want to live long, don’t shoot yourself in the head, or you might die’), but it cannot tell us for which ends we ought to aim, or why.

Though Michael Nowak himself is an observant Christian, there will no doubt be those who seek to use (or abuse) his ideas, as they have done with others, to further their aim of explaining the meaning of life, love, and everything else, without reference to the human soul or to God. Yet there is something ironic about those who rubbish religious truths as mere fables all the while credulously swallowing modern day myths about alcoholic monkeys from Scandinavia and the many other fanciful tales put out by some scientists to explain this or that human trait. It is an irony so delightful that only God could have conceived of it.

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(photo of Deutsch-Ostafrika, Schimpanse Hamiss: © German Federal Archive)

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