Brain Size Has Nothing To Do With High IQ, New Meta-Analysis Finds
If you wanted to be seen as someone with a high IQ, would you change anything about your appearance? Maybe you’d say the size of your head. After all, the more room you have for your brain, the bigger your brain will be, and the higher your IQ will be. If this is what you thought, then you’d be wrong. As one study published in Neuroscience and Behavioral Reviews points out, a larger-sized brain doesn’t necessarily equate to a higher IQ.
Scientists from Austria, the Netherlands, and Germany collected data from 88 published and unpublished studies encompassing nearly 8,000 participants to confirm that brain size does not equal a high IQ. "Although a certain association is observable, brain volume appears to be of only little practical relevance," said lead author Jakob Pietschnig, from the Institute of Applied Psychology at the University of Vienna, in a press release.
From the 148 healthy, mixed-sex brain samples they were able to analyze, they found that although there might be a small link between brain size and IQ, it is really how your brain is structured that influences your intelligence. Pietschnig explained, “Brain structure and integrity appear to be more important as a biological foundation of IQ, whilst brain size works as one of many compensatory mechanisms of cognitive functions." In other words, your brain’s size only determines the quickness in which cognitive functions are completed.
Why do so many people believe brain size is linked to high intelligence? The researchers believe that 150 years of confirmatory associations between brain size and intelligence are a factor, and they blame it partly on publication bias. This bias comes along when published studies suggest strong links connecting brain size and IQ, while studies turning up weak or inconclusive links fall by the wayside — this is also why Pietschnig and his team looked at both published and unpublished studies.
The researchers’ claims that a large brain size doesn’t equal a high IQ is supported by a simple fact: Men have bigger brains than women, but there is not a significant difference between men and women’s IQ test scores. As recently as 2012, researchers found that women score higher on IQ tests than men. The intelligence line is slightly blurred, however, as research has also found that men and women tend to be smarter than the other in certain categories. This, along with other evidence, may suggest IQ tests aren’t even the best way to determine a person’s intelligence.
Source: Pietschnig J, et al. Meta-analysis of associations between human brain volume and intelligence differences: How strong are they and what do they mean? Neuroscience and Biobehavioral Reviews. 2015.