summary of Sex differences in children's conversation are explored to determine if they exist and, if so, when they emerge. Forty preschool children were randomly assigned to groups (female-female, female-male, male-male) and were audio-taped in conversation while playing. Transcripts of their conversations were analyzed for interruptions, overlaps, lapses, gaps and number of initiated unit-types. Significant differences between heterogeneous and homogeneous groups were found for interruptions. Boys interrupted girls 2 to 1. Conversational sex differences seem to be acquired early in life, developing in conjunction with general conversational skills.​