Number 96 : April 1999 |
A number of contributors to Commensal (C87/11, C88/13, C88/21) have recently questioned the basis of IQ testing and its predictive value. They are not alone; for many years, going back to the beginnings of intelligence testing early this century, various aspects of IQ have been questioned. The opponents may be put into two classes : those within the psychometric community, and those outside it. In the 1930s and '40s Thurstone maintained that the data from intelligence tests could be interpreted not as giving rise to one number (the g of Spearman, the basis of IQ) but to several numbers associated with different intellectual abilities. Subsequently many researchers have followed this line.
Outside the psychometric community many distinguished people (eg. the late Peter Medawar) have maintained on general philosophical grounds that the abilities of an individual should not be represented by one or even several numbers. Others, notably members of the discipline of cognitive neuroscience, maintain that the vast amount of work devoted to psychometry over many years, in particular IQ testing, has done very little to increase our understanding of how the mind works.
Although the origin of intelligence testing at the turn of this century was in Europe (Alfred Binet in Paris, Charles Spearman in London, William Stern in Leipzig) interest and research moved rapidly to the USA. Of recent years the subject there has become polarized politically, a prominent example being the Bell Curve book. Right-wing opponents of massive spending by the state on the education of the poor have used arguments based on IQ, and opponents of IQ testing have been dismissed as Marxists. A recent issue of Scientific American gives a good survey which includes the American situation.
Interest in Europe in the subject has been less of late, though much research has been done, eg. in Marburg and Tübingen, into the problem of identifying and treating gifted children and Kline at Exeter continues the psychometric tradition. The mathematical basis of testing has been strengthened by the work of Jöreskog in Uppsala.
Many fat books have been devoted in recent years to the IQ controversy, most of them American and most of them, as my history master used to say, tendentious. However several books have appeared lately in the UK discussing the subject in a more dispassionate way, notably those of P Kline and N J Mackintosh.
Victor Serebriakoff's words : "Its general truth [of IQ testing] is not in doubt except where doubt is an act of political faith" and "....the fiercest attack upon the idea of mental testing arises out of left wing dogma" are far from reality. If you are interested in the IQ debate I urge you to get hold of the following books and articles :-
Alan Edmonds
Alan : Thanks for that succinct critique ! So, just what (if anything) do IQ tests measure ? Whenever I’ve raised the matter in ISPE I’ve always been savaged by individuals with a lot of "facts" at their finger-tips (and more interest in the subject that I have) who claim that factor analysis shows that g is well-founded. There are many issues you don’t address (not that this is a fault !), though I’d be interested if you or others could pick up on them. You don’t cover why some people perform better than others, and fairly uniformly so, nor whether these abilities (or propensities to acquire them) are genetically inherited or learned. Nor whether, however measured, there do indeed exist innate differences in ability between individuals; nor how this affects their worth (if it does) ... what is valuable to a society, etc.
Theo