Neuropsychiatric diseases like schizophrenia are the result of processes acting on time scales of both an individual’s lifetime and our species’ history. For this reason, insights into human brain development or brain evolution in general can also help to elucidate related aspects of brain disorders. Specifically, the mammalian brain is characterized by a six-layered cerebral cortex which folds up with increasing brain size. Abnormalities in the thickness and folding of the cerebral cortex have been observed in patients with schizophrenia, autism, William’s syndrome, and other medical conditions. We therefore investigate the common principles underlying these processes by quantifying brain shape, both in humans (particularly children) and across species (particularly other primates) on the basis of data obtained with Magnetic Resonance Imaging.