WAIS or MRI? The Future of IQ Testing

image: Guardian

Since the turn of the century, psychometricians like Alfred Binet and David Wechsler have been measuring the Intelligence Quotient (IQ) of both children and adults using various testing methods. The most popular of these methods has been the psychological test. Whether written, verbal, or behavioural, these tests have always had one common thread: they all determine intelligence based on individual demonstration. But is that the only way of discerning intelligence?

Researchers Liye Wang and colleagues at the Beijing Institute of Technology may be on to the future of intelligence testing, and it doesn’t involve testing at all, but imaging. Through the use of Magnetic Resonance Imaging (MRI), Wang et al. examined the relationship between features of gray matter and white matter in various areas of the brain, and their respective relationship to IQ. But, can it be as reliable a source as traditional IQ testing? Through examining MRI samples of 164 typically developing children, the researchers concluded results comparable to many of the written tests over the years (correlation coefficient of ~.72). What, then, are the implications of such findings?

Wang et al. conclude that their method of discerning intelligence is as accurate as many psychological tests, so why not do away with other forms of testing altogether? Firstly, the average cost of an MRI is around $2,600. Compare that with the average cost of an IQ test, which often runs around $700 dollars, at most. Secondly, the steep cost of medically non-urgent MRIs may be an unnecessary burden on healthcare, whereas traditional paper-and-pencil testing avoids medical treatment settings completely. Lastly, though MRI is generally considered to be harmless, the safety of gadolinium-based contrast materials (used to enhance the visibility in MR images) has recently been called into question.

Considering the economic burden placed both on the individual and the economy, not to mention the question of procedure-related safety, intelligence testing in its traditional form may be safe from the realm of obsolescence. However, this may only be the beginning of a future where neural-imaging grows safer and less costly every year, and radiologists may one day supplant psychometricians in determining what makes us who we are.

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