A perturbation paradigm was employed to assess 3- and 6-month-old infants' and their mothers' sensitivity to a 3-s temporal delay implemented in an ongoing televised interaction. At both ages, the temporal delay affected infant but not maternal behavior and only when implementing the temporal delay in maternal (Experiment 1, N = 64) but not infant (Experiment 2, N = 60) behavior. In addition, the experimental manipulation influenced promptness of maternal smiling responses reliably more than promptness of infant smiling responses. The findings suggest that the timing of maternal behavior plays an important role in infants' perception of maternal responsiveness, whereas mothers seem to monitor general aspects of infant behavior such as overall level of engagement.