Larger brains do not lead to high IQs

Is brain size related to cognitive ability of humans? This question has captured the attention of scientists for more than a century. An international team of researchers from the Universities of Vienna (Austria), Göttingen (Germany), and Tilburg (Netherlands) provides no evidence for a causal role of brain size for IQ test performance. In a meta-analysis of data from more than 8000 participants, they show that associations between in-vivo brain volume and IQ are small. As early as 1836, the German physiologist and anatomist Friedrich Tiedemann, in an article in the Philosophical Transactions, expressed his opinion that "there is undoubtedly a connection between the absolute size of the brain and the intellectual powers and functions of the mind". With the advent of brain imaging methods (e.g. MRI, PET), reliable assessments of in-vivo brain volume and investigations of its association with IQ are now possible. Now, an international team of researchers, led by University of Vienna researchers Jakob Pietschnig, Michael Zeiler, and Martin Voracek from the Faculty of Psychology, together with Lars Penke (University of Göttingen) and Jelte Wicherts (Tilburg University), published a meta-analysis examining correlations between in-vivo brain volume and IQ in Neuroscience and Biobehavioral Reviews.