Abstract
Joint attention (JA), which develops in rapidly humans immediately after birth, is important in subsequent social cognitive development. Since this topic was introduced in 1975, although the definition and behavioral indices of joint attention have come to be broadly interpreted and diverse, the initial emergence of joint attention behavior and the developmental relation among joint attention behaviors have yet to be investigated. The present study reports the results of a survey of longitudinal research on joint attention in approximately 2,000 infants (ages 8-18 months), including infants with typical development, mental retardation, and autism, in which the infants were assessed every 2 months. The analysis revealed the initial emerging periods of joint attention behavior. A joint attention behavior scale was developed and standardized. Four related developmental stages were proposed. The results should enable effective developmental assessments. Early predictors of autism were discussed, as was typical joint attention behavior in 18-month-old infants.
