Evolutionary Perspective on Human Growth

To better understand both the shared and special features of human growth, this article explores the evolution of growth patterns of mammals in general and primates in particular. Special attention is paid to several competing hypotheses concerning the adaptive value of the juvenile stage to the life history of the social mammals. One hypothesis claims that all social mammals have a juvenile stage of life, but although most primate species are social, not all primates show a juvenile stage of life history. There is also controversy over whether the adolescent growth spurt is a uniquely human feature. On the basis of empirical observations and evolutionary considerations, I conclude that the human adolescent growth spurt in stature and skeletal maturation is species specific, not found in any other primate species. Finally, data and theory are used to advance a philosophy of human growth. An acceptable philosophy must acknowledge the mammalian and primate foundations for the human pattern of growth. But a robust philosophy of human growth must also account for the ecology to which the human species, indeed any species, is adapted. Accordingly, a philosophy of human growth must allow for the evolution of variations on common themes and of new stages of growth that may be unique to the human species.