In the late 1960s, after a period of intense acceleration of the pace of research on human infancy, a number of investigators – some anthropologists, some psychologists, some psychiatrists and paediatricians, and even a few ethologists – developed the conviction that certain contributions to the understanding of infancy would come from, and perhaps only come from, cross-cultural and cross-population studies.This book, originally published in 1981, represents part of the first fruit of that conviction, and its impressive range of chapters justifies not only the belief itself but also the several rationales behind it.