One in a series on comparative cognition and neuroscience, this volume seeks to investigate the cognitive development of nonhuman primates within the framework of the human developmental states set forth by Piaget. Thus, it attempts to bridge the gap between human and nonhuman primates and to relate the phylogenetic differences in states attained by lower primates to those experienced sequentially by human children. It is severely hampered in this effort by a lack of information from the abundant literature on free-living, nonhuman primates (e.g., there is not a single reference to any of Goodall\u27s published work). All the findings come from strictly Piagetian, laboratory, or zoo studies of developing animals. Chapters include both repor...