Development is slow in many primates, particularly so in humans, as key skills needed for survival and successful reproduction have to be acquired. In one of human’s closest living relatives, the chimpanzee, there is surprisingly little data on developmental processes. Researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have now systematically investigated developmental milestones in wild chimpanzees of the Taï National Park (Ivory Coast) and found that they also develop slowly, requiring more than five years to reach key motor, communication and social milestones. This timeframe is similar to humans, suggesting slow maturation of the brain.