Hippocrates, American Renaissance, August 2010
The Flynn Effect (FE) has become the accepted term for the increase in IQs that has been reported in many developed countries during the 20th century. The FE has also recently been reported in two developing countries, Dominica and Sudan.
In fact, the term Flynn Effect is a misnomer, because the rise of IQs was first shown in the United States in 1948 by Read Tuddenham, in a comparison of the IQs of the military drafts in 1917 and in World War II. In 1949 a similar rise of IQ, from 1932 to 1947 was reported in Scotland. These increases were subsequently found in a number of other countries before Professor James Flynn, emeritus professor at the University of Otago in New Zealand, rediscovered them in 1984. An IQ increase was reported for Japan in 1982 by Professor Richard Lynn and the rise has sometimes been called the Lynn-Flynn Effect. Use of the term “the Flynn Effect” violates the convention that scientific discoveries be named after those who discovered them, such as Boyle’s law and Mendelian genetics. The increase in IQs should properly be called the Tuddenham Effect.
Let us consider the main facts about the FE and then the theories that have been proposed to explain it. The main facts are, first, that IQ scores increased in many countries by about 3 IQ points every decade from 1917 up to around the year 1990. During the last 20 years or so these increases have stopped in Denmark and gone into reverse in the United States, Britain, and Norway. Second, the FE has taken place mainly for reasoning ability and very little for verbal comprehension or mathematical-spatial ability. Third, the FE has occurred principally among the less intelligent, which is to say that averages have risen mainly because of the gains among people of lower rather than higher IQ. Fourth, in the United States, the FE has taken place at the same rate for blacks and whites.
There have been three principal theories to explain the FE. Professor Flynn initially took the view that “real intelligence” has not increased at all, because obviously young people today are not much more intelligent than their grandparents. What had increased must have been the ability to do better on intelligence tests. However, in his 2007 book What is Intelligence? he changed his mind. He now believes that there have been improvements in education that have led to more scientific and logical thinking (“science has engendered a sea change . . . formal education played a proximate role”) and this has caused a real increase in reasoning ability.
Prof. Flynn also believes that the ability to think more scientifically and logically is transmitted by association: “[T]he IQ of our social environment is a potent influence on our own IQ.” This leads him to predict that people who live in a university town will have higher IQs than those who do not, because the high IQs of professors will raise the IQs of the population. This is extremely unlikely because it has been found that the IQs of adoptive parents have no long-term effect on the IQs of their adopted children. If growing up with smart parents doesn’t raise your IQ, living in the same town with smart people is hardly going to make a difference.
The principal alternative theory of the FE is that the main cause of the IQ increase has been improvements in nutrition. This would have resulted in increases in height as well, and would have produced better neurological development of the brain and larger brain size. In developed countries, increases in height ceased about 1990, at about the same time as the increases in IQs ceased. In further support of this theory, it has been shown that the FE can be found in two-year-olds, which rules out the theory that it has been caused by improvements in education.
One of the puzzles of the FE is that it suggests American blacks today are smarter than whites were in the 1920s. As IQs increased by about 3 IQ points a decade during the 70 years from 1917 up to around the year 1990, the IQs of both blacks and whites increased by 19 IQ points, so if the IQs of blacks and whites are set at 85 and 100 (respectively) in 1917, the average IQ of blacks in 1990 was 104 and that of whites was 119. This raises the problem of why blacks, with their increased IQs, have not produced the geniuses that whites with the same IQ produced in the 1920s. There are about 32 million blacks in the United States, accounting for about 12 percent of the population. The United States has won 46 Nobel Prizes in the sciences from 2000 to the present, but none by blacks.
There are three possible answers to this problem. First, blacks still score 15 IQ points lower than whites, so there are many fewer black geniuses. Second, the range of IQ is lower among blacks, so there are fewer blacks with very high IQs. Third, blacks may lack the persistence required for the sustained effort necessary to do the work necessary to win a Nobel Prize. Professor Michael Levin hints at this in his book Why Race Matters, in which he suggests that blacks have what economists call a “high time preference,” i.e. they prefer present pleasures over deferred rewards: “The central motivational difference between blacks and whites may be said to be higher black time preference” (p.78).
This is closely related to the fact that blacks appear to be different from whites not just in average intelligence but in what could be called “average personality,” and this also could contribute to racial differences in achievement. In July 2002, AR published an article called “Race and Psychopathic Personality,” which explored this question in detail. Even when whites and blacks are matched for IQ, blacks still commit crime at 2.5 times the white rate, suggesting that something other than intelligence explains group differences.
Research on personality consistently shows that blacks have higher levels of psychopathy, originally identified in 1837 as “moral imbecility” by the English physician J.C. Pritchard, and recently replaced with the softer term, “anti-social personality disorder.” An early definition of psychopathic personality described it as general poverty of emotional feelings, lack of remorse or shame, superficial charm, pathological lying, egocentricity, a lack of insight, absence of nervousness, an inability to love, impulsive antisocial acts, failure to learn from experience, reckless behavior under the influence of alcohol, and a lack of long-term goals. There is a normal distribution of psychopathic tendencies in all populations, and blacks seem to have markedly higher average levels than whites — who, in turn, have higher levels than East Asians. These tendencies do not lead to success in many fields other than crime and politics.
As noted above, during the last 20 years or so, IQs have declined in the United States, Britain, and Norway. The most likely explanation for this is that nutrition reached its optimum around 1990, so the IQ increases ceased. In the last two decades, IQs have declined because the more intelligent have been having fewer children than the less intelligent. This is known as dysgenic fertility, and has been a characteristic of economically developed nations since the closing decades of the 19th century. Because intelligence is transmitted from parents to children, the effect of this is that the intelligence of each generation of children falls, once the advantages of improved nutrition have been exhausted. This fall is now taking place and can be expected to continue.
Flynn, J.R. What is Intelligence? Cambridge University Press, 2007.
Levin, M. Why Race Matters. Praeger, 1997.
Lynn, R. What has caused the Flynn effect? Secular increases in the development quotients of infants. Intelligence, 2009. 37, 16-24.
Pritchard, J.C. A Treatise on Insanity. Harwell, Barrington & Harwell, 1835.
Tuddenham, R. D. Soldier intelligence in World Wars I and II. American Psychologist, 1948, 3, 54-56.