Observed home interaction between parents and 2- and 4-year-olds at Time 1 and 2 years later. Found that parent mental state talk to children varied by child's age, context of talk, and parent gender. Four-year-olds with older siblings produced and heard more cognitive talk and less desire talk than children without older siblings. Time 1 family cognitive and feeling talk predicted change in younger children's cognitive and feeling talk. (Author/KB)