We don't know exactly what it measures, but we are not surprised that myelination[0] and dendrite length[1] increase with IQ. [0]https://www.nature.com/article

We don't know exactly what it measures, but we are not surprised that myelination[0] and dendrite length[1] increase with IQ. [0]https://www.nature.com/articles/s41380-017-0001-5 https://www.nature.com/articles/s41380-017-0001-5 [1]https://www.nature.com/articles/s41467-023-39946-9 https://www.nature.com/articles/s41467-023-39946-9