TED日本語 - ジェームズ・フリン: なぜ祖父母世代よりもIQが高いのか

We are going to take a quick voyage over the cognitive history of the 20th century, because during that century, our minds have altered dramatically. As you all know, the cars that people drove in 1900 have altered because the roads are better and because of technology. And our minds have altered, too. We've gone from people who confronted a concrete world and analyzed that world primarily in terms of how much it would benefit them to people who confront a very complex world, and it's a world where we've had to develop new mental habits, new habits of mind. And these include things like clothing that concrete world with classification, introducing abstractions that we try to make logically consistent, and also taking the hypothetical seriously, that is, wondering about what might have been rather than what is.

Now, this dramatic change was drawn to my attention through massive I.Q. gains over time, and these have been truly massive. That is, we don't just get a few more questions right on I.Q. tests. We get far more questions right on I.Q. tests than each succeeding generation back to the time that they were invented. Indeed, if you score the people a century ago against modern norms, they would have an average I.Q. of 70. If you score us against their norms, we would have an average I.Q. of 130. Now this has raised all sorts of questions. Were our immediate ancestors on the verge of mental retardation? Because 70 is normally the score for mental retardation. Or are we on the verge of all being gifted? Because 130 is the cutting line for giftedness.

Now I'm going to try and argue for a third alternative that's much more illuminating than either of those, and to put this into perspective, let's imagine that a Martian came down to Earth and found a ruined civilization. And this Martian was an archaeologist, and they found scores, target scores, that people had used for shooting. And first they looked at 1865, and they found that in a minute, people had only put one bullet in the bullseye. And then they found, in 1898, that they'd put about five bullets in the bullseye in a minute. And then about 1918 they put a hundred bullets in the bullseye. And initially, that archaeologist would be baffled. They would say, look, these tests were designed to find out how much people were steady of hand, how keen their eyesight was, whether they had control of their weapon. How could these performances have escalated to this enormous degree? Well we now know, of course, the answer. If that Martian looked at battlefields, they would find that people had only muskets at the time of the Civil War and that they had repeating rifles at the time of the Spanish-American War, and then they had machine guns by the time of World War I. And, in other words, it was the equipment that was in the hands of the average soldier that was responsible, not greater keenness of eye or steadiness of hand.

Now what we have to imagine is the mental artillery that we have picked up over those hundred years, and I think again that another thinker will help us here, and that's Luria. Luria looked at people just before they entered the scientific age, and he found that these people were resistant to classifying the concrete world. They wanted to break it up into little bits that they could use. He found that they were resistant to deducing the hypothetical, to speculating about what might be, and he found finally that they didn't deal well with abstractions or using logic on those abstractions.

Now let me give you a sample of some of his interviews. He talked to the head man of a person in rural Russia. They'd only had, as people had in 1900, about four years of schooling. And he asked that particular person, what do crows and fish have in common? And the fellow said, "Absolutely nothing. You know, I can eat a fish. I can't eat a crow. A crow can peck at a fish. A fish can't do anything to a crow." And Luria said, "But aren't they both animals?" And he said, "Of course not. One's a fish. The other is a bird." And he was interested, effectively, in what he could do with those concrete objects.

And then Luria went to another person, and he said to them, "There are no camels in Germany. Hamburg is a city in Germany. Are there camels in Hamburg?" And the fellow said, "Well, if it's large enough, there ought to be camels there." And Luria said, "But what do my words imply?" And he said, "Well, maybe it's a small village, and there's no room for camels." In other words, he was unwilling to treat this as anything but a concrete problem, and he was used to camels being in villages, and he was quite unable to use the hypothetical, to ask himself what if there were no camels in Germany.

A third interview was conducted with someone about the North Pole. And Luria said, "At the North Pole, there is always snow. Wherever there is always snow, the bears are white. What color are the bears at the North Pole?" And the response was, "Such a thing is to be settled by testimony. If a wise person came from the North Pole and told me the bears were white, I might believe him, but every bear that I have seen is a brown bear." Now you see again, this person has rejected going beyond the concrete world and analyzing it through everyday experience, and it was important to that person what color bears were -- that is, they had to hunt bears. They weren't willing to engage in this. One of them said to Luria, "How can we solve things that aren't real problems? None of these problems are real. How can we address them?"

Now, these three categories -- classification, using logic on abstractions, taking the hypothetical seriously -- how much difference do they make in the real world beyond the testing room? And let me give you a few illustrations.

First, almost all of us today get a high school diploma. That is, we've gone from four to eight years of education to 12 years of formal education, and 52 percent of Americans have actually experienced some type of tertiary education. Now, not only do we have much more education, and much of that education is scientific, and you can't do science without classifying the world. You can't do science without proposing hypotheses. You can't do science without making it logically consistent. And even down in grade school, things have changed. In 1910, they looked at the examinations that the state of Ohio gave to 14-year-olds, and they found that they were all for socially valued concrete information. They were things like, what are the capitals of the 44 or 45 states that existed at that time? When they looked at the exams that the state of Ohio gave in 1990, they were all about abstractions. They were things like, why is the largest city of a state rarely the capital? And you were supposed to think, well, the state legislature was rural-controlled, and they hated the big city, so rather than putting the capital in a big city, they put it in a county seat. They put it in Albany rather than New York. They put it in Harrisburg rather than Philadelphia. And so forth. So the tenor of education has changed. We are educating people to take the hypothetical seriously, to use abstractions, and to link them logically.

What about employment? Well, in 1900,three percent of Americans practiced professions that were cognitively demanding. Only three percent were lawyers or doctors or teachers. Today,35 percent of Americans practice cognitively demanding professions, not only to the professions proper like lawyer or doctor or scientist or lecturer, but many, many sub-professions having to do with being a technician, a computer programmer. A whole range of professions now make cognitive demands. And we can only meet the terms of employment in the modern world by being cognitively far more flexible. And it's not just that we have many more people in cognitively demanding professions. The professions have been upgraded. Compare the doctor in 1900, who really had only a few tricks up his sleeve, with the modern general practitioner or specialist, with years of scientific training. Compare the banker in 1900, who really just needed a good accountant and to know who was trustworthy in the local community for paying back their mortgage. Well, the merchant bankers who brought the world to their knees may have been morally remiss, but they were cognitively very agile. They went far beyond that 1900 banker. They had to look at computer projections for the housing market. They had to get complicated CDO-squared in order to bundle debt together and make debt look as if it were actually a profitable asset. They had to prepare a case to get rating agencies to give it a AAA, though in many cases, they had virtually bribed the rating agencies. And they also, of course, had to get people to accept these so-called assets and pay money for them even though they were highly vulnerable. Or take a farmer today. I take the farm manager of today as very different from the farmer of 1900. So it hasn't just been the spread of cognitively demanding professions. It's also been the upgrading of tasks like lawyer and doctor and what have you that have made demands on our cognitive faculties.

But I've talked about education and employment. Some of the habits of mind that we have developed over the 20th century have paid off in unexpected areas. I'm primarily a moral philosopher. I merely have a holiday in psychology, and what interests me in general is moral debate. Now over the last century, in developed nations like America, moral debate has escalated because we take the hypothetical seriously, and we also take universals seriously and look for logical connections. When I came home in 1955 from university at the time of Martin Luther King, a lot of people came home at that time and started having arguments with their parents and grandparents. My father was born in 1885, and he was mildly racially biased. As an Irishman, he hated the English so much he didn't have much emotion for anyone else. (Laughter) But he did have a sense that black people were inferior. And when we said to our parents and grandparents, "How would you feel if tomorrow morning you woke up black?" they said that is the dumbest thing you've ever said. Who have you ever known who woke up in the morning -- (Laughter) -- that turned black?

In other words, they were fixed in the concrete mores and attitudes they had inherited. They would not take the hypothetical seriously, and without the hypothetical, it's very difficult to get moral argument off the ground. You have to say, imagine you were in Iran, and imagine that your relatives all suffered from collateral damage even though they had done no wrong. How would you feel about that? And if someone of the older generation says, well, our government takes care of us, and it's up to their government to take care of them, they're just not willing to take the hypothetical seriously. Or take an Islamic father whose daughter has been raped, and he feels he's honor-bound to kill her. Well, he's treating his mores as if they were sticks and stones and rocks that he had inherited, and they're unmovable in any way by logic. They're just inherited mores. Today we would say something like, well, imagine you were knocked unconscious and sodomized. Would you deserve to be killed? And he would say, well that's not in the Koran. That's not one of the principles I've got. Well you, today, universalize your principles. You state them as abstractions and you use logic on them. If you have a principle such as, people shouldn't suffer unless they're guilty of something, then to exclude black people you've got to make exceptions, don't you? You have to say, well, blackness of skin, you couldn't suffer just for that. It must be that blacks are somehow tainted. And then we can bring empirical evidence to bear, can't we, and say, well how can you consider all blacks tainted when St. Augustine was black and Thomas Sowell is black. And you can get moral argument off the ground, then, because you're not treating moral principles as concrete entities. You're treating them as universals, to be rendered consistent by logic.

Now how did all of this arise out of I.Q. tests? That's what initially got me going on cognitive history. If you look at the I.Q. test, you find the gains have been greatest in certain areas. The similarities subtest of the Wechsler is about classification, and we have made enormous gains on that classification subtest. There are other parts of the I.Q. test battery that are about using logic on abstractions. Some of you may have taken Raven's Progressive Matrices, and it's all about analogies. And in 1900, people could do simple analogies. That is, if you said to them, cats are like wildcats. What are dogs like? They would say wolves. But by 1960, people could attack Raven's on a much more sophisticated level. If you said, we've got two squares followed by a triangle, what follows two circles? They could say a semicircle. Just as a triangle is half of a square, a semicircle is half of a circle. By 2010, college graduates, if you said two circles followed by a semicircle,two sixteens followed by what, they would say eight, because eight is half of 16. That is, they had moved so far from the concrete world that they could even ignore the appearance of the symbols that were involved in the question.

Now, I should say one thing that's very disheartening. We haven't made progress on all fronts. One of the ways in which we would like to deal with the sophistication of the modern world is through politics, and sadly you can have humane moral principles, you can classify, you can use logic on abstractions, and if you're ignorant of history and of other countries, you can't do politics. We've noticed, in a trend among young Americans, that they read less history and less literature and less material about foreign lands, and they're essentially ahistorical. They live in the bubble of the present. They don't know the Korean War from the war in Vietnam. They don't know who was an ally of America in World War II. Think how different America would be if every American knew that this is the fifth time Western armies have gone to Afghanistan to put its house in order, and if they had some idea of exactly what had happened on those four previous occasions. (Laughter) And that is, they had barely left, and there wasn't a trace in the sand. Or imagine how different things would be if most Americans knew that we had been lied into four of our last six wars. You know, the Spanish didn't sink the battleship Maine, the Lusitania was not an innocent vessel but was loaded with munitions, the North Vietnamese did not attack the Seventh Fleet, and, of course, Saddam Hussein hated al Qaeda and had nothing to do with it, and yet the administration convinced 45 percent of the people that they were brothers in arms, when he would hang one from the nearest lamppost.

But I don't want to end on a pessimistic note. The 20th century has shown enormous cognitive reserves in ordinary people that we have now realized, and the aristocracy was convinced that the average person couldn't make it, that they could never share their mindset or their cognitive abilities. Lord Curzon once said he saw people bathing in the North Sea, and he said, "Why did no one tell me what white bodies the lower orders have?" As if they were a reptile. Well, Dickens was right and he was wrong. [ Correction: Rudyard Kipling ] [ Kipling ] said, "The colonel's lady and Judy O'Grady are sisters underneath the skin."

(Applause)