Systematic observations of parent-child interaction in Mexican families revealed a number of reciprocal patterns of behaviour. Warm, supportive parent behaviour was found to be positively related to both supportive and to assertive, self-expressive child behaviour. Punitive, restrictive parent behaviour and parental attempts at "psychological control" were found to be positively related both to passively resistant and provocatively resistant child behaviour. In addition, sex differences were found in the dyadic patterns that emerged. The implications of these findings, with a focus on how parent-child interaction patterns may affect children's social and emotional development, are discussed from a within-and cross-cultural perspective.