Our brain develops differently than the chimp's brain:-"The analysis is the first to show this "hour glass" sketch of human brain development, with a lull in genetic activity sandwiched between highly complex patterns of gene expression, said Nenad Sestan, professor of neurobiology at Yale's Kavli Institute for Neuroscience and senior author of the study. Intriguingly, say the researchers, some of the same patterns of genetic activity that define this human "hour glass" sketch were not observed in developing monkeys, indicating that they may play a role in shaping the features specific to human brain development"-http://medicalxpress.com/news/2013-12-human-brain-symphony-movements.html