Sensitivity to timing in interaction was assessed in mother-infant interaction. In Study 1, three-month-old infants were presented with an image of their mother interacting with them on television, which was either live or temporally delayed by 1 second. Infants detected the temporal delay and were more attentive when the mother was presented live compared to delayed by 1 second. In Study 2, mothers interacted with an image of their three-month-old infant, which was either live or temporally delayed by 1 second. Mothers did not respond to a 1-second delay in their infants' behavior. In Study 3 and 4, the results were replicated with six-month-old infants