In view of the fact that the brain more than doubled in the last two million years before Homo Sapiens appeared and that intelligence is at a premium since we left hunter-gathering then it is probably still our fastest-changing faculty and being selected for.
We know that, in the last 10,000 years, there have been evolutionary changes in our dentition and also in mutations which allows us to digest milk and have resistance to certain diseases. What we don’t know for certain, because we have no possible standard IQ test that could have been applied all the way through the last 10,000 years, is whether our intelligence has been increasing.
The fact that we have become increasingly specialised in our skills since 10,000 years ago is highly suggestive that our intelligence has been growing. It is highly unfeasible that the number of specialisations could have grown while general intelligence was declining. Mind you, IQ tests can only measure a few mental parameters. Because scores are generally correlated with general intelligence then IQ tests are useful when selecting people for averagely skilled jobs or below. They are increasingly useless when selecting for highly-skilled jobs.
While a person of higher intelligence can fairly accurately assess the intelligence of a lower-skilled person — that is, in terms of an IQ score — after conversing for a few minutes, he or she would require many conversations to make a shrewd estimate of the intelligence of someone with an IQ score close to their own and impossible if talking to a person of much higher intelligence apart from recognizing its presence. For example, it is rumoured that, some years ago, when Goldman Sachs was much smaller, job candidates were interviewed 10 times by 10 separate partners in the firm. Even then it was many years before that had a chance of being made partners.
While size and brute force — abundant health — is the desired quality for the pecking order of the group — and the ultimate leadership — in the lower social mammals, the more that intelligence would have become necessary in the primates that evolved to us during the 2.5 million years on the African savannah when it was wracked by repeated changes in temperature and tree cover as the 20 or so Ice Ages swung back and forth and we experienced precarious living conditions. Intelligence had to emerge as a principal quality that needed to be selected.
We can assume, then, that the increasing specialisations of the leading advanced countries — that is, those with significant numbers of scientific research labs able to throw up innovations and yet more specialisations — leads to elites of higher intelligence than average. A BBC television/internet survey of IQ scores in England some 30 years ago — and too politically dangerous ever to have been repeated — showed a 10-point divide between people in the north versus the south. This is understandable because almost all the highly talented or ambitious young people have been migrating to London from the north (and Scotland) for amany years.
There’s another strong factor operating here. Sociologists call it ‘assortative mating’ –ike tends to marry like. In other words the English elite of higher intellgence in London and the south will tend to marry other members of the elite. A high proportion of marriages in the present London elite met while undergraduates at Oxford and Cambridge.
Evolutionary biologists have a more specific term for ‘assortative mating’ — ‘sympatric separation’. This not only includes the separation aspect but also that females choose males from as high up the social scale as they can, usually within their class but, quite often, into a higher class. Beautiful females can do so very effectively. As beauty is genetically correlated with intelligence and heath, the London elite is not only rending to keep high intelligence there by inter-marriage but also with the bonus of intelligent females entering from below.
I’ve often written about sympatric separation and each time wondered whether I was over-egging it. The one thing that could defuse a build-up of high intelligence in London is more Free Schools which would compensate for the selective grammar schools which a Labour government scrapped. However, more recent information shows that about six out of seven new Free Schools are being established in London so, if anything , the separation effect will be even more concentrated.
Whether sympatric separation will proceed even further until we have what are two virtual sub-species — alpha-man and beta-man — I don’t know. Probably, egalitarians will become very agitated about this but as it’s a voluntary trend I don’t see how it can be prevented. Suffice it to say that this happens in a lot of species and it’s happened in man’s past, too. On the basis of fossil evidence so far, it looks as though there could have at least a dozen such separations, or brachiations, into two branches, and then one died out. So the question remains: Are we being divided?