I followed a link posted by a friend on facebook, to this interesting article which cites a study that claims that Human intellect peaked a few thousand years ago and has been declining since. The gist of the argument is that “Since the invention of agriculture and cities, however, natural selection on our intellect has effective stopped and mutations have accumulated in the critical “intelligence” genes” and so we’re less intelligent now than our ancestors in early agricultural settlements. While it sure is an interesting hypothesis, I’m not convinced that it has any substance in it. In fact, I think this theory is full of holes.

From a genetics point of view (and the Professor Gerald Crabtree who proposed this hypothesis heads a genetics lab), all that I could find in there was that there have been many mutations in intelligence related genes in the last 3000 years, but nothing is known about the effect of these mutations on our intelligence. So based on the the information we have, our analysis can be based only on the logical arguments proposed, which is what I want to take a shot at.

The very first question that this study raises is the definition of intelligence. If we take it to mean the ability to learn and memorize, I am sure an average high-school student of today will have learnt more complex concepts and memorized more data than “an average citizen from Athens of 1000BC “. This does not prove that the Athenian is incapable of learning or memorizing, but that he had less to learn and memorize because of a smaller knowledge base within his reach. However, this indicates that successful kids of today (who manage to learn and memorize more than their peers) who are likely to be selected by nature to bear the seeds of the next generation are more likely to be selected based on intelligence than any of their other traits (except luck, perhaps).

Now, if the proponents of this hypothesis we were to define intelligence by what Athenians were apparently good at, which is “a broad range of ideas and a clear-sighted view of important issues“, I am not sure how our generation is in anyway behind. For example, in that age, would a person like me even come to know such a research going on in another part of the world – much less have an opinion about it? (Please don’t let my focus on this perhaps unimportant issue prejudice your opinion about the intelligence of this age!). This again does not anything about the capacity for philosophical thought among those who lived in 1000 BC and the ones who live now. However, going by this yardstick, what is the chance that intelligence had any role in the natural selection of hunter-gatherers?

When it comes to talking about the hunter-gatherer, the professor makes a sharp deviation in his definition of intelligence from what he said about the Athenian man “A hunter-gatherer who did not correctly conceive a solution to providing food or shelter probably died, along with his or her progeny” – ok, so here’s no talk about the broad range of ideas. If we take these survival skills of a hunter-gatherer for intelligence, then modern man may be at a disadvantage, but so will be the average Athenian.

I partly agree when it says “…whereas a modern Wall Street executive that made a similar conceptual mistake would receive a substantial bonus and be a more attractive mate“. But this ireference is only to a failed system and not to today’s world or the human race at large. In fact, when a system starts rewarding failure, it itself fails and paves way for more successful systems which value success and thus selects the most able thinkers. This can be seen as the underlying force in the decline of almost every civilization in human history – stagnation and deterioration. And this has always let other societies grow, come to the fore, contribute new ideas, and make humanity at large richer.

Now, if the system does not fail even after favouring the incapable (such as bailing out a failed corporation or reserving jobs and promotions for certain classes), it also makes life a struggle for the others. So among these others, natural selection becomes even more decisive, and their bloodline is likely to get highly refined in relatively fewer generations. So if and when a time comes such that the system is corrected or the talented ones take control, the pampered classes will be quickly wiped off by the magical wand of natural selection.

The only aspect where I think we may be on the decline  is our spiritual side, being more and more materialistic as we go. But that is clearly not the point made by Professor Gerald Crabtree and, so, can be the subject of another post (if at all necessary to touch upon). Finally, let me congratulate you on reading through to the end of this long article. It shows there still are very intelligent humans around 🙂