Friday, 14 February 2014

Speculative implications of living in a world with a very rapid (? two IQ points per decade) decline in average intelligence



sykes.1 said...

In Darwinian theory, "a world where natural selection is now for pure fertility" is the only world. Evolutionary works entirely by differential reproduction, and characters are selected for to the extent that they are hereditable and contribution to fertility.

As to the result of declining IQ, it is Detroit for everyone. Idiocracy is not sustainable. The incompetent herd will not be able to sustain the economy, technology and culture. The Latin American phenomenon of a rich, cultured ruling class sitting on top of a large underclass cannot happen.

Bruce Charlton said...

@Sykes 1 - No - reproductive success is the product of more than fertility. In particular it depends on mortality - and in human history reproductive success was dominated by differential child mortality rates.

Thus, until a couple of hundred years ago, all classes and types of people had well above replacement fertility levels - and the difference was whether the children that were born survived to adulthood (and reproductive maturity).

Nowadays, everywhere in the world and among all classes, just about every child born will grow to adulthood - but in the developed world fertility is well below replacement levels (less than two and a bit children per woman).

This is the first time in human history that child mortality has been so low that reproductive success is pretty-much purely fertility driven.

Of course this is unsustainable. The only question - a big question indeed - is when and how it will stop.