If we look across many, many different species of animals, not just us primates, but also including other mammals, birds, even marsupials like kangaroos and wombats, it turns out that there's a relationship between how long a childhood a species has and how big their brains are compared to their bodies and how smart and flexible they are.
Se observamos varias especies distintas, non só outros primates coma nós, senón tamén outros mamífeors, paxaros, incluso marsupiais coma os canguros ou os vombátidos, resulta que hai relación entre a duración da infancia, e o tamaño relativo do cerebro e a intelixencia e flexibilidade da especie.