COMMENTARY DIALOGICAL NATURE OF COGNITION Philippe Rochat The overarching message of this monograph is that cognition and cognitive development are inseparable from social adaptation. Although not new, this message has often tended either to be ignored or to take a backseat in the quest for a machinelike description and explanation of cognition and its development. The report of Jaffe, Beebe, Feldstein, Crown, and Jasnow is another wake-up call to the danger of splitting the cognitive from the social. The complex and careful observations reported in this monograph demonstrate that from the origins of development children do not con- strue the world in independence of the process by which they establish relationships with other individuals. After reading the report of this re- search, one should be convinced that the study of cognitive processes (thinking, reasoning, problem solving, concept formation, etc.) cannot and should not be divorced from social processes that allow the individ- ual to commune with others, to manage social proximity, and to search for intimacy. There are two parts to my commentary. First, to complement Jaffe and collaborators’ findings I offer some considerations regarding impor- tant developmental changes marking the 1st year of life. My point is that we should avoid the temptation to reduce infants to a fixed quantity of intelligence or interpersonal skills that would explain long-term pre- dictions and stability of behavioral outcome, whether IQ or attachment patterns. In fact, the story is much more complex, involving major devel- opmental transitions and changes between birth and age 12 months. In the second part of this commentary, I make a theoretical plea for the socially grounded nature of cognition. This plea is inspired by the re- markable findings compiled in this monograph. These findings demonstrate 133