This study examined sequential dependencies in behavior of 10 mother-infant dyads recorded when the infants were at 7 and 20 weeks of age in an effort to determine the extent to which individuals behave responsively to their partners during interactions. Ten maternal actions and 10 infant actions were selected in face-to-face interactions. Actions were selected on the basis of their relatively high frequency of occurrence and their assumed role in social interactions. Results showed that mothers were consistent in their selective responsiveness to infant acts, while infants showed little selectivity in their behavioral responses to maternal acts except at 20 weeks. (Author/SH)