More on Intelligence and Heritability

[Taraz]

Last week I had the pleasure of attending a talk given by James Flynn, a prominent intelligence researcher who has tried to explain what is known as the Flynn Effect. He raised some very interesting ideas and theories that I thought many of you would enjoy.

Basically, the Flynn Effect refers to the universal rise of IQ scores across the globe over time. Scores have risen continuously since the inception of the tests and this poses a problem for those who believe that genes are the dominant determinant of intelligence. If environment only plays a small part and intelligence is mostly about your genes, why would we see such huge IQ gains from generation to generation?

He did a remarkable job of explaining why the concept of general intelligence, or g, is flawed and actually blinds us to what might actually be occurring. He points to the fact that IQ tests with similar g-loadings (the degree to which a test reflects g) have had quite disparate gains over time.

The thrust of his argument is the proposal of what he termed the Dickens/Flynn model of intelligence. It was pretty stunningly brilliant in it's simplicity. Your genes will have a profound effect on your subsequent environment throughout life. He gave the analogy of identical twins separated at birth who happen to be a bit taller than average due to their genetic makeup. In elementary school, they will be picked first on the playground to play basketball because of their height. This might lead them to prefer basketball over other sports. In middle school, the coaches might see their height advantage and spend a bit more time instructing them. In high school they will receive even more special attention and so on. By the time they reach college, they have received a ton more attention and instruction in basketball than their peers, only it is their genes that are given the credit! Basically, a small genetic difference gets compounded many times by environmental factors and results in a large difference when it is all said and done.

If you have a small genetic advantage in intelligence, your teachers may pick up on it and treat you differently. Research has already shown that teacher perception can vastly increase performance in the classroom even if that perception is false. You will then be placed in the honors tracks and get even more attention, etc., etc. So while it may seem that the intelligence displayed by a bright adult is due to a genetic advantage, this individual has actually received an huge environmental advantage because of this genetic advantage.

I want to note that Flynn believes that genes do play into the equation, but that environmental factors are far, far more explanatory than genetics. If you are interested I found a short article he wrote about the subject, it's really cool stuff.

http://www.cato-unbound.org/2007/11/05/j...-interventions/