IQ and equality

Boris Johnson says (pdf):

It is surely relevant to a conversation about equality that as many as 16% of our species have an IQ below 85, while about 2% have an IQ above 130.

It might be relevant, but not in the way he intends.

The fact that 16% have IQs below 85 tells us not about people, but about the way standard IQ tests are constructed. They are designed so that it's always the case that 16% have a sub-85 IQ. This doesn't mean that IQ is fixed; the Flynn effect tells us it isn't.

However, whilst the distribution of IQs is fixed, the distribution of income isn't. The share going to top incomes - which I think is the relevant one in this context given Mr Johnson's talk of the 2% with IQs above 130 - shows a big U-shape over the last century.

This simple juxtaposition tell us that IQ alone doesn't much influence inequality; something that doesn't change can't explain something that does.

Of course, it could be that what's changed is the payoffs to IQ. The collapse in demand for unskilled workers in the west since the 1970s and rise in "winner-take-all" markets might mean that low-IQ is now penalized more than it was in the 60s and 70s, whilst a high IQ reaps bigger rewards.

Whilst these trends are undoubtedly important, I'm not sure they are strongly related to IQ. The correlation between IQ and incomes is low; many bosses, remember, fail basic maths. And insofar as there is a correlation, it is due in part to poverty causing low mental functioning and IQ tests favouring richer people's minds rather than to IQ causing income. In implying otherwise, Mr Johnson seems to be making that common error of the rich, of confusing success and merit.

But let's assume all this is false, and there were a link between IQ and inequality. Would this then mean inequality is tolerable? Not at all, for two reasons.

First, a link between IQ and income does not - in itself - tell us anything about the justice of a social system. If a dictator allocated jobs according to IQ, or if high-IQ people were better at stealing from others, there'd be a strong link between IQ and income. But this wouldn't mean the systems were just.

Secondly, a person's IQ is (largely) beyond their control. And one common principle of justice is that people should not suffer because of things they cannot control. If you think low IQ causes poverty, therefore, you might well reasonably think there's a strong case for redistribution. As John Rawls said, the distribution of talent is "arbitrary from a moral point of view":

There is no more reason to permit the distribution of income and wealth to be settled by the distribution of natural assets than by historical and social fortune. (A Theory of Justice, p74).

Sure, Rawls might be wrong. But this should be argued for - and Mr Johnson doesn't do this.

In claiming that IQ is relevant to a conversation about equality, then, Mr Johnson is wrong  empirically. And even if he were right, IQ would be relevant in the opposite way from which he intends - because inequality of IQ might actually justify more egalitarian policies, and not an acceptance of inequality.

Comments

[Callum McPherson]

Why don't you write in the guardian? It would make such a change from the usual unsubstantiated hokum. Also, there is something amusing about someone getting their facts wrong while complaining about people of a low IQ. If Boris becomes PM I'm emigrating...

[Churm Rincewind]

I can't imagine why you're taking such an inane remark so seriously.

On second thoughts, though, I rather despairingly suppose it's important that such silliness is clearly refuted.

[rogerh]

The IQ idea is politically useful - it hides the more truthful reality that home+life experience+school+IQ are the real factors that affect likely success. IQ looks politically neutral, the others desperately poliitical. One factor can compensate for others and you can send your kids to a 'good school' if you have the money. In the end wealth becomes self sustaining and can survive most catastrophies. To probe the equity of this process is to invite trouble.

Should we treat low IQ as some sort of disability? - well at the extreme we do. But as for the mid-range - I can imagine the testing regime would be politically poisonous. A can of worms.

Were I a mandarin considering spending extra money to even up this playing field the question of efficiency might come to mind - if I boosted housing, education and life experience for the poorer people just how many extra top CEOs, surgeons and quantum physicists do I get for my (lots of) money. Then I might look at the cost of imports.

[Dave Levy (@DaveLevy)]

@rogerh nice!

Boris deliberately ignores the fact that it isn't IQ that determines income distribution, its class; and a market that values derivative traders or music executives more than care assistants or fire fighters.

[TickyW]

@Chris

Your readers may be interested in some number crunching of HMRC data on the distribution of UK income

http://theuxbridgegraduate.wordpress.com/2013/09/29/definitively-rich/

[Stephen]

"Of course, it could be that what's changed is the payoffs to IQ. The collapse in demand for unskilled workers in the west since the 1970s and rise in "winner-take-all" markets might mean that low-IQ is now penalized more than it was in the 60s and 70s, whilst a high IQ reaps bigger rewards."

I'm sure it pays to be smart in some walks of life (engineering, computing, high freq trading?) but it probably always has. I suspect the change is not so much income as the increased importance of wealth leveraging wealth - property, shares, land etc. This is why it is so grating to listen to the wealthy bloviating on their own merits as if they were all Steve Jobs meets James Dyson.

[Martin]

"low-IQ is now penalized more than it was in the 60s and 70s"

Agreed. Also back then there was more paternalism, which can protect those with low cognitive ability. (This has me conflicted since I have anti-paternalist priors.)

One correction: your link to an alleged "low" correlation of IQ and income actually shows a fairly high correlation.

There is also a high correlation between national IQ and national income
http://en.wikipedia.org/wiki/IQ_and_the_Wealth_of_Nations

[andrew]

If a dictator allocated jobs according to IQ, or if high-IQ people were better at stealing from others, there'd be a strong link between IQ and income. But this wouldn't mean the systems were just.

... true

And one common principle of justice is that people should not suffer because of things they cannot control.

... not true

I think what you were thinking of was

Article 25.

(1) Everyone has the right to a standard of living adequate for the health and well-being of himself and of his family, including food, clothing, housing and medical care and necessary social services, and the right to security in the event of unemployment, sickness, disability, widowhood, old age or other lack of livelihood in circumstances beyond his control.

So, not only not true but you are asserting that people in 'poverty' are 'suffering'.

When people in poverty in the mass are unable to have a spare bedroom, I do not think you can call it suffering.

[Tim S]

Boris Johnson, that semi aristocratic, super privileged, very wealthy, totally connected, privately educated otherworldly posh person talks about why people are poor and some are rich??!! Because dear Boris, some of the rich have connections and inherited wealth like you, and many of us don't. I think people in glass houses should not throw stones basically.

[Miguel Madeira]

«One correction: your link to an alleged "low" correlation of IQ and income actually shows a fairly high correlation. »

Looking to the link, I don't see nothing about the value of the correlation, only graphs - then, I think it is difficult to see if the correlation is high or low.

[Keith]

andrew millions of people are being impoverished by the Government Boris and you support so they are quite right to be annoyed. Why does the state have the right to tell poor people how many rooms they should need but not the well off? Your observations have nothing to do with the discussion and are an attempt to derail it. Boris is so wrong he clearly needs your diversion to protect him. Poor baby.

[Jackart]

Boris made exactly that point which is why he praised the rich for paying lots and lots of tax, and called for more charitable giving from them. He just came to it from a different angle. Which leads me to suspect you read the Guardian's report about the speech, but not the speech itself.