(A) Events presented in studies 1 to 3. The order of the presentation of the videos (parent first or other parent yoked control condition first) was counterbalanced across infants, as was the puppet that was imitated and the pair of puppets that appeared with each adult. In study 2, the puppets appeared on screen in silence following the parent videos. In study 3, the puppets appeared with music in the background instead of in silence. In both studies 2 and 3, the puppets then appeared facing the infant and a voice spoke in a friendly manner using the infant’s name. (B: Infants’ reaching for the imitated puppet (study 1, stacked bars) and proportion of time looking at the imitated puppet (studies 2 and 3, box plots; white dots are means, black bars are medians; connected dots are a single infant’s data; boxplots made with ggplot2 (27).