Evidence for 'motionese': modifications in mothers' infant-directed action

We investigated the possibility that mothers modify their infant-directed actions in ways that might assist infants' processing of human action. In a between-subjects design, 51 mothers demonstrated the properties of five novel objects either to their infant (age 6-8 months or 11-13 months) or to an adult partner. As predicted demonstrations to infants were higher in interactiveness, enthusiasm, proximity to partner, range of motion, repetitiveness anti simplicity, indicating that mothers indeed modify their infant-directed actions in ways that likely maintain infants' attention anti highlight the structure and meaning of action, The findings demonstrate that 'motherese' is broader in scope than previously recognized, including modifications to action as well as language.