The Daily Mail headline is “IQ tests are ‘meaningless and too simplistic’ claim researchers.” CBC News headline: “IQ myth debunked.” Wasn’t I just saying yesterday that there’s a bias against IQ?
So, I checked the abstract of the paper that’s being reported with these sensational headlines. Here it is:
Fractionating Human Intelligence
Adam Hampshire, Roger R. Highfield, Beth L. Parkin, Adrian M. Owen
We propose that human intelligence is composed of multiple independent components
Each behavioral component is associated with a distinct functional brain network
The higher-order “g” factor is an artifact of tasks recruiting multiple networks
The components of intelligence dissociate when correlated with demographic variables
What makes one person more intellectually able than another? Can the entire distribution of human intelligence be accounted for by just one general factor? Is intelligence supported by a single neural system? Here, we provide a perspective on human intelligence that takes into account how general abilities or “factors” reflect the functional organization of the brain. By comparing factor models of individual differences in performance with factor models of brain functional organization, we demonstrate that different components of intelligence have their analogs in distinct brain networks. Using simulations based on neuroimaging data, we show that the higher-order factor “g” is accounted for by cognitive tasks corecruiting multiple networks. Finally, we confirm the independence of these components of intelligence by dissociating them using questionnaire variables. We propose that intelligence is an emergent property of anatomically distinct cognitive systems, each of which has its own capacity.
Neuron, Volume 76, Issue 6, 1225-1237, 20 December 2012 Copyright © 2012 Elsevier Inc. All rights reserved. 10.1016/j.neuron.2012.06.022
The brain uses different networks for different tasks, but it also uses multiple networks together. Intelligence is an emergent property: that is not the same a “myth” or something “meaningless”. Plenty of things are emergent properties, which means they should not and cannot be reduced to their components.
Update (Jan 2, 2013):
James Thompson on his blog Psychological Comments shows that this study has severe problems. Its sample of people neuroimaged is just 16. The sample of those doing online IQ tests is in the thousands, but are self-selected, doubtless from the higher end of the spectrum, where the correlation among different cognitive tests is weaker than across the whole spectrum.