 In terms of brain size differences, it has been noted that given the larger skull in neoteny humans, brain volume may be larger than an average human brain.It has been hypothesized that this is one mode of which the brains of Homo sapiens grew as a species, as the prolonged development of neurons may have led to hypermorphosis, or excessive neuronal growth.Especially in the prefrontal cortex, brain pruning from childhood may be slower than usual, allowing for more time for neuronal maturation.