peak size occurring at 11.3 in girls and 15.6 in boys, similar to the cerebrum. However, these different subregions appear to follow different developmental trajectories. In contrast to the evolutionarily more recent cerebellar hemispheric lobes that followed the inverted U shaped developmental trajectory, cerebellar vermis size did not change across the age span covered in this study (5–24 years) (Tiemeier et al. 2009).
