James Flynn discovered the Flynn Effect
, the steady worldwide increase in IQ scores, and is justly famous for it. He's been wondering about the implications of his discovery ever since, and in this book tries to summarise his thoughts. Unfortunately, he waited until he was 73 before publishing, and it shows. When I read it, I imagined sitting in a lecture hall, listening to him give a series of talks. You'd never know what to expect. Sometimes he'd be on form and come out with some amazingly insightful stuff. Sometimes he'd ramble, or spend the whole hour on one of his hobby-horses. But I'd have continued to attend, because the good bits were worth the annoyance.
The Flynn Effect is paradoxical, something that Flynn is well aware of. In fact, he starts by listing the various paradoxes involved. Here are the ones I found most interesting:
1. IQ scores keep going up, but people don't appear obviously smarter. Why? It's easy to wonder if the tests are measuring anything real.
2. If the tests are in fact measuring something real, then most people 100 years ago had IQs that now would put them in the bottom 10% or even the bottom 2% of the scale. How could they function in day-to-day life? Evidently, most people then could get by just as well as they do now, and maybe even better.
3. The IQ gains can't be due to genetic processes, since they have happened far too quickly. They have to be due to environmental changes. But, in many studies, in particular ones with identical twins separated at birth, you can see that IQ is largely inherited. How can environment have made such a huge difference in one case, but not in the other?
Flynn has an interesting explanation for these facts; I don't know if I buy it 100%, but at least it seems better that anything else I've seen. I'll start by looking at his criticisms of rival theories. The first thought that occured to me is that people have simply learned to be more skillful at doing IQ tests. I'm sure that it's possible
to learn to do IQ tests much better by practicing in the right way, and I'm also sure that some people (Mensa, I'm looking at you) have been doing this. But Flynn argues convincingly that it doesn't explain the very steady increase we see in IQ scores from more than 30 different countries. The rise started well before IQ tests were common, hence before most people would even have thought of preparing for them, and it continued at the same rate after IQ tests became less popular, which would have given people less motivation. So this theory doesn't stand up to careful examination.
The most popular explanation, which is the one you see in the Wikipedia article on the Flynn Effect, is that it's due to better nutrition, either in early infancy or pre-natally. Flynn's archrival, who oddly enough is called Lynn, claims that this is the only account which makes sense: he sees it as decisive that the increases in IQ score show up even in very young children. This is indeed odd. But Flynn produces an even more decisive bit of evidence in the opposite direction. The Netherlands has detailed, comprehensive results for IQ testing over a long period, which is where the Flynn Effect was first noticed. Now there was an appalling famine in the Netherlands during 1944 - Germany was losing the war, food was short, and they just decided that most of it was going to go to the German occupiers. The Dutch nearly starved. If nutrition were key, you'd expect a dip in the IQ curve for children born around that time, but there is no dip at all. Hence the nutrition theory can't be right either.
So here's what Flynn thinks has happened. He claims that there's been a systematic, large-scale shift in cognitive patterns over at least the last 100 years, driven by the increasingly important role that science and technology have played in people's lives. In particular, it's meant that people are more and more able to think abstractly as well as concretely: IQ tests are very much about capturing the ability to think abstractly, and it makes a large difference to the score. The changes in cognitive style are so much a part of the fabric of society that we don't see them, but when you compare people's way of thinking today with the way they thought a hundred years ago, it's noticeable. Flynn says he started thinking about this stuff when he saw interviews that the great Luria had conducted with rural Russians, who indeed found it almost impossible to think abstractly or hypothetically. I loved the following example:
Luria: Where the land is always covered in snow, bears are white. Novaya Zemlya is always covered in snow. What colour are the bears in Novaya Zemlya?
Peasant: I have only seen black bears. I do not speak of that I do not know.
Luria: But, if someone saw bears on Novaya Zemlya, what colour would they be?
Peasant: If a man had been to Novaya Zemlya and told me he had seen white bears there, I might believe him.
It's hard to imagine a normal Western adult talking like this today, but it does seem to fit the picture of an uneducated Russian peasant that I've got from reading 19th century novels. Things have changed.
Another example that Flynn discusses several times comes from questions on similarities, an important component of several of the standard IQ tests. Suppose the subject is asked "What do dogs and rabbits have in common?" A hundred years ago, when IQ tests were just getting started, it was apparently common to answer "You use dogs to hunt rabbits". This isn't exactly wrong, but it isn't what you're supposed to say either: in the scoring instructions, the person administering the test is directed to give the subject no points if they answer in this way. The correct answer is "Both are mammals". These days, most average kids have unconsciously picked up enough of the scientific world-picture to know that this is what is intended. 100 years ago, only an exceptional child would do so.
Obviously, one anecdotal example can be explained in many ways. Flynn argues that all sorts of cognitive patterns which we now take for granted are of quite recent vintage, and that ability to use these patterns represents a real increase of intelligence which is being picked up by IQ tests. A particularly striking one is "percentage": according to Flynn, this idea is only about 160 years old. Imagine not being able to manipulate the concept of a percentage, and learning to do it. You would feel a bit smarter! Flynn gives many more examples. People may find some of them provocative: in particular, he considers that inability to understand the fallacy of the Intelligent Design argument shows you're stupid, and the fact that more people realise it's wrong is evidence of increasing intelligence. Feel free to storm out of the lecture hall if you don't like this.
Going back to less contentious questions, one of the great merits of Flynn's account is that it explains how people 100 years ago could have had IQs much lower than we have today, and yet have had no problems in day-to-day life. The main reason why people get better scores today is that they are better at abstract/hypothetical thinking, but day-to-day thought in a rural environment is largely about concrete things. If one of Luria's peasants had taken a modern IQ test he might have flunked all the questions about abstract reasoning, but that wouldn't necessarily have affected his ability to run his farm. Most people today are not farmers. If you're working at a tech startup in Silicon Valley, you can't do your job without constantly using abstract and hypothetical reasoning.
Flynn's model also explains why environment seems so much more important across generations than it does in identical twin studies. Identical twins, by definition, are born at the same time, and will grow up in cognitive environments typical of the same moment in history. When you compare across generations, you're comparing people who have substantially different cognitive frameworks. Here was another analogy that I liked. Suppose IQ were shooting: you compare scores for marksmanship across a period going from the Civil War to World War II, where the task is to put as many bullets as possible into a target within one minute. A Civil War soldier would be doing well to manage five bullets, but a World War II soldier might get 50 without even trying. It's not a fair comparison, because only one of them has a machine-gun. The implication is that scientific thought now gives us a mental machine-gun, whereas previously we only had a mental rifle. At first, I was sceptical, but the more I thought about it the more I liked it; we really have found useful new ways to think about things. To take a recent example, just stop for a moment and consider how illuminating it can be to conceptualise the mind as a piece of software, and all the useful metaphors it can give you. ("I must have had a bug!" "I think we've got an interface problem?") Only an exceptional person could have thought like this in 1950, but now it's natural for anyone who has a laptop or a cellphone.
Flynn views himself as a philosopher rather than a psychologist - his heroes are Aristotle and Plato - and the book is in that direction. There are more thought experiments than I would ideally have liked, and fewer controlled studies. As noted, he has an infuriating tendency to ramble. But he's an interesting and original thinker, and he's posing some important questions I hadn't previously seen stated this clearly. It's well worth reading.