The IQ question
Thu, 03 Nov 2011 14:20:00 GMT
ARTICLES, conference papers and a forthcoming book by a visiting senior research fellow at the University of Huddersfield could mean that psychologists throughout the world begin to reduce their level of dependence on long-established but flawed IQ tests as a principal means of establishing intellectual disability.
The implications are immense – for the psychology profession, for social and health workers and even the courts. Dr Simon Whitaker (pictured) , who is also a Consultant Clinical Psychologist for South West Yorkshire Partnership NHS Foundation Trust, argues that IQ tests should only be one tool among many in making a diagnosis.
It is a widely-adopted convention that an IQ level of 70 is regarded as a cut-off point for establishing intellectual retardation. Whether a person scores above or below that figure can determine whether or not he or she receives social services. And the grimmest scenario is in the US courts, where the death penalty cannot be handed down to anybody deemed to have a mental retardation.
But Dr Whitaker’s research has shown that there are significant errors of measurement in IQ tests, so that somebody who scores over 70 might still have a learning disability.
When, over the course of two weeks, he and colleagues subjected a group of 16-year-olds to the two most well-respected IQ tests: the Wechsler Intelligence Scale for Children 4th edition (WISC-IV) which assessed the intelligence of children between 6-16 age, and the Wechsler Adult Intelligence Scale 3rd edition (WAIS-III), that measures the intellectual ability of adults between the ages of 16 and 90 – Dr Whitaker discovered that there was an enormous 12-point variation between the average scores obtained on the two tests.
“So what is their true IQ?” he asks.
Dr Whitaker’s work in the field of IQ has also looked at the “Flynn effect”. Named after the New Zealand psychologist James R. Flynn, it shows that the intellectual ability of the human population has been rising at a rate of three IQ points per decade.
Research by Dr Whitaker has uncovered inconsistencies in the Flynn effect and this led him to conclude that IQ tests need to be reappraised. Another of his articles – written with his ex-student Carmen Laird – found that much of the recent scientific literature on the subject was failing to take into account the errors in measurement that were occurring in IQ tests.
“The problem is that people place a lot of faith in IQ tests. You have these scientific –sounding results and so everybody thinks it’s objective. A lot of people assume that the measurement of IQ is like the measurement of height.”
Dr Whitaker believes that psychologists will have to adopt a new approach to learning disabilities and how they are defined. The history of each individual would have to be examined and if they were failing to cope, a decision would have to be made on whether or this was due to intellectual problems or some other cause.
In arguing against over-reliance on IQ testing, Dr Whitaker acknowledges that he is up against some vested interest. But he also believes that his ideas are gaining recognition, and his work is widely cited.
“You realise that a lot of psychologists in this field have had these sorts of suspicions themselves, so I feel I am pushing at an open door. Quite why nobody has done what I have surprises me!”
Dr Whitaker’s most recent articles are published in the current issue of the British Journal of Developmental Disabilities. He is now working on a book that will summarise his findings after eight years of research in the field of IQ.
“My conclusion will be that we should change the definition of learning disabilities to something that is overtly subjective, based on whether an individual is managing to cope or not.”
