I was once sat next to an economist. He asked me what I did for a living and I told him.
“Education is all about signalling,” he explained. It turns out that ‘Signalling Theory’ was his specialist subject.
“Take art history degrees, for example,” He continued, “they are of no real use. What you are really saying by doing an art history degree is that you are smart otherwise you wouldn’t invest so much time and money in completing one. This is then what you are signalling to a future employer.”
I don’t know about art history degrees – maybe he’s onto something there – but as a general theory of education, signalling theory sucks.
This is because intelligence is two things and yet people invariably think of it as just one.
The first component of intelligence is raw processing power. This is how much you can manipulate in your working memory. We might call this ‘fluid intelligence’ and there is not much you can do about it. People have devised ‘brain training’ activities that attempt to improve fluid intelligence through exercise, as if it were a muscle. The evidence suggests that this kind of exercise makes you very good at the training task but that this doesn’t transfer to anything else.
When some people argue that intelligence being hereditary then it might be because of genes that determine fluid intelligence. If that’s the case then what is the point of all of this education? Our intelligence is preordained.
But there is another component to intelligence that we might call ‘crystallised intelligence’. Loosely, this is what you know. If you know your multiplication tables then you might be able to solve multiplication problems more quickly and accurately than someone who has greater fluid intelligence than you but who doesn’t know their tables.
Consider two plumbers. One is a smart trainee and the other is an old hand. Who will solve the plumbing problem first? Well the old hand will have plenty of previous plumbing problems to compare it to, a process that will happen without conscious effort. This is greater crystallised intelligence.
Education is the process of growing the crystallised intelligence of individuals. Unfortunately, we cannot predict the future either in general terms or the future for any particular individual. We do not know what mental resources they might want or need. So we make a best guess. We teach them that which has endured on the plausible assumption that knowledge that has proved useful or fulfilling in the past will do so in the future.
It is possible that crystallised intelligence has a genetic component. People might inherit personality traits that make them more inclined to stay indoors and read books. Yet I think that most of the time the nature versus nurture people are talking past each other.
Those who believe that intelligence is largely genetic conceive of it as the fluid component only and those who want to stress a growth mindset are actually conceiving of intelligence as the crystallised component. This latter group don’t seem to realise this and talk as if they are somehow growing the brain through exercise. They are not.
My economist had made the error of thinking of intelligence as only the fluid component and so had undervalued the role of knowledge. I tried to explain this to him but he seemed to struggle to grasp what I was taking about.
Perhaps he wasn’t very smart.