Contents: Part I:Introduction.Antinucci, The Comparative Approach to the Study of Cognition. F. Antinucci, The Theoretical Framework. Part II:Longitudinal Study of Cognitive Ontogeny: Birth to Stage 4.G. Spinozzi, F. Natale, Early Sensorimotor Development in Gorilla. P. Poti, Early Sensorimotor Development in Macaques. G. Spinozzi, Early Sensorimotor Development in Cebus. F. Antinucci, Systematic Comparison of Early Sensorimotor Development. Part III:Cognitive Domains.F. Natale, Stage 5 Object-Concept. F. Natale, F. Antinucci, Stage 6 Object-Concept and Representation. G. Spinozzi, P. Poti, Causality I: The Support Problem. F. Natale, Causality II: The Stick Problem. Part IV:Structure and Development of Logical Cognition.F. Antinucci, Introduction to the Study of Logic. F. Natale, Patterns of Object Manipulation. G. Spinozzi, Francesco Natale, Classification. P. Poti, F. Antinucci, Logical Operations. J. Langer, Comparison with the Human Child. Part V:Conclusion.F. Antinucci, On the Phylogeny of Human Cognition.