Carpendale & Lewis's (C&L's) theory falls in with an existing set of theories that children's understanding of mind is collaboratively constructed in linguistically mediated social interaction. This social constructivist view needs to be clear about the complementary contributions of the child and of the social environment. I distinguish between the child's individual linguistic ability and the dyad's social communication, proposing that each makes a contribution to theory-of-mind development, differently balanced in different individuals.