Play-solicitation gestures in chimpanzees in the wild: flexible adjustment to social circumstances and individual matrices
Whether language/gesture correlations in early language development can be explained by parallelism or comprehension mediation was examined. Study 1, parental report data for 95 l-year-olds, suggested that word comprehension and production are dissociated in this age range and that the comprehension and production factors map onto distinct aspects of gesture. Study 2 tested 41 13-15month-olds in a task in which the modeled gesture was accompanied by supportive, contradictory, or neutral narratives. Results showed that infants can use adult speech as an aid in reproduction of modeled gestures (comprehension mediation). However, there is still additional variance in gestural production that correlates with expressive vocabulary when comprehension-related variance is removed. Thus, comprehension mediation and parallelism both appear to be operating.