Brain size
![Average brain weight for males and females over lifespan. From the study Changes in brain weights during the span of human life.](/Images/godic/202501/06/Brain_weight_age5433.gif")
The size of the brain is a frequent topic of study within the fields of anatomy and evolution. Brain size is sometimes measured by weight and sometimes by volume (via MRI scans or by skull volume). Neuroimaging intelligence testing can be used to study brain size. One question that has been frequently investigated is the relation of brain size to intelligence.