Our prefrontal cortex is massive compared to that of other species. In the human adult, the prefrontal cortex constitutes nearly one-third of the neocortex, which is the entire part of the brain involved in higher-order brain functions. By comparison, the prefrontal cortex makes up just 17 percent of the neocortex in a chimpanzee, 13 percent in a dog, and 4 percent in a cat.
