The Emergence of Intentional Communication in Ontogeny, Phylogeny, and Pathology

The emergence of intentional gestural communication around the end of the first year of life is widely recognized as a basic milestone in the infant's communicative development. Two types of comparison are carried out in this paper. The first comparison concerns the gestural communication of human infants and of our nearest primate relatives, the apes, and especially the well-studied chimpanzees. The second comparison considers a special case of gestural communication, namely children with autism, who fail to develop some important forms of communication, language, and social interaction that normal infants develop in the first 2 years of life. In seeking to explain the patterns of similarities and differences derived from these two comparisons, the possible role of several developmental processes will be considered and evaluated: social sensitivity, sensitivity to eye contact and gaze, understanding of agency, and understanding of subjectivity.