Posted by Pete Hague on 19 Jul 2012
A recent news story has prompted me to talk about something that I've wanted to discuss for a while - the problems inherent in the concept of IQ. The story, mostly picked up by the right-wing press going by my Google News results, states that women have overtaken men in IQ scores. This produced a predictably angry response from many people commenting on the Internet.
Lets get the required scientific skepticism out of the way - this has the hallmarks of a university press release being regurgitated by lazy journalists, and the underlying quality of the work is by no means assured. But let us give the benefit of the doubt for a moment, and say that the Telegraph and the Mail have accurately reported on some scientific conclusions that are actually supported by data.
The meat of the story is that as a group, women have a 5 point IQ lead on men. The first thing to note is that the standard deviation on an IQ test is normally 15 points (apologies for the source, but given most information online about IQ tests is designed to sell stuff to people who think they or their children are gifted, Wikipedia starts to look pretty solid.) Finding a difference of 1/3 of a standard deviation between two normal distributions is essentially a non-result, as can be demonstrated by overlaying two such distributions:
This leads to a more qualitative point; the variation between individuals being substantially larger than the variation between groups (men and women in this case) means that looking at a persons group identity is entirely useless for assessing their intelligence. So, even if IQ is a good proxy for intelligence, and even if the research is correct - it tells us nothing of use, nor anything that should change the way we act or any government policy.
This matter is more complicated when group differences are supposedly on the same scale as individual variation; in the book The Bell Curve it was (in)famously claimed that in the US, there was a substantial difference between the average black IQ (85) and the average white IQ (103). This result has been the subject of years of intense discussion, which I'm neither inclined nor properly qualified to comment on. Suffice to say, there are complicating factors which mean you should take it with a serious pinch of salt.
How is an egalitarian-minded person to deal with this information? You can't simply tell yourself it is factually wrong unless you know the field and can read through all the relevant literature yourself. From what little I've read, with no knowledge of the appropriate fields, it is unfounded - but likely in the future other similar claims will come up. If one of them stands up to scientific scrutiny, does a rational person suddenly have to become a racist?
Unless you want to start cherry picking what scientific hypotheses you consider probable based on your political preferences, you need to find a way to reconcile your beliefs even in the (unlikely) event the above result, or a similar one, is correct. Note that I personally do not see any evidence that meaningful genetic disparities in IQ exist (once you've factored in people being malnourished and denied education etc.) - but I have no purely rational basis for saying that such a disparity could never, ever be demonstrated. I could conceivably be wrong.
Rejecting the notion of group identity is obviously an important step in resolving this. If you test someones IQ, the result of that test does not change after the fact if you then find that people who share superficial physical characteristics have lower or higher IQs. Even if that characteristic has any potential to predict IQ at all, you don't need to use it - because it is straightforward enough to measure the IQ of anyone if you need to know it.
But, of course, this still all assumes that IQ means anything at all. To really be able to accept the reality, but reject the relevance and meaningfulness, of a politically disquieting IQ disparity, it might be best to question what the point of IQ is at all.
I think its fair to say, as I have done before, that our society has something of a fixation on intelligence. There is a keen urge to rank everybody according to intellectual merit, and IQ facilitates that quite nicely. It reduces anything that could be considered intelligence to a single number, and one that is normally distributed amongst the population - so that for any value of IQ, you can very simply work out what fraction of the population you are "smarter" than.
In case it wasn't clear, I see this as being a problematic approach. I don't think human capabilities are simple enough to be put on a single axis. Some have proposed developing 5 different quotients to measure different aspects, but I need to be convinced that even that 5 dimensional space can enclose all human mental ability.
But the real question is - why do we have to rank people at all? In debate, it is considered an ad hominem logical fallacy to measure the validity of an argument by some characteristic of the person making it. The same surely applies in other walks of life - you can't reliably predict the quality of someones words or actions by any measure of their brain, no matter how accurate (I believe that such a predictive method could be reduced to the halting problem and thus be shown to be mathematically impossible.) If a supposed measure of intelligence can't tell you anything in advance about what a person is intellectually capable of, it doesn't serve any really useful purpose.
I accept the need for assessment to assign people to various professional positions - but in the real world, such assessment recognises its lack of predictive ability by being continuous throughout a persons career. In many walks of life, you are only considered as good as your most recent work. Metrics of intelligence such as IQ subvert that, essentially claiming that you are as good as this single test you did one time. Unsurprisingly then, IQ is not often used as an assessment in industry or academia. Maybe, then, people should avoid thinking in terms of a fixed, quantifiable intelligence.
I debated whether or not to include this section. When I was a teenager, and having problems at school, a child psychologist gave me a standard IQ test. The result was initially hidden from me, on the basis that knowing it might make me even more of a pain in the arse at school - but I found out regardless. I learned that my IQ was 152, more than three standard deviations above the mean and statistically higher than 99.97% of the population.
I was invited to join a high-IQ society - but to quote my dad from memory "If you are paying money for someone to tell you that you are a genius, how smart can you be?". Having avoided the more obvious pitfall of IQ-elitism, I did fall into another. I acted as if my apparent intelligence alone was proof of my intellectual awesomeness, and there was no need for me to put effort in. This wasn't helped by the number of occasions at school and university where this seemed to actually be the case.
In time, I came to realise something important; if you are the smartest person in the room, then you must be in the wrong room. Either that, or perhaps you aren't as smart as you think you are. The only way to differentiate is by your actions. Being numerically labelled as intelligent has been of no use to me at all.