In healthy volunteers, total brain volume weakly correlates with intelligence, with a correlation value between 0.3 and 0.4 out of a possible 1.0. In other words, brain size accounts for between 9 and 16 percent of the overall variability in general intelligence.
Does cranial capacity relate to intelligence?
Cranial capacity was measured in people with known IQs. A very small correlation was found between cranial capacity and intelligence; but this was shown to be the result of the confounding effects of height. A large series of brains was also investigated, data being obtained on occupation from the case notes.
What does cranial capacity indicate?
Cranial capacity is a measure of the volume of the interior of the skull of those vertebrates who have a brain. The most commonly used unit of measure is the cubic centimetre (cm3).
