title: Social initiative and temperament in the second year.
mesh_terms: D005260:Female; D006801:Humans; D007223:Infant; D007398:Interpersonal Relations; D008297:Male; D009035:Mothers; D010379:Peer Group; D010551:Personality; D010988:Play and Playthings; D002666:Psychology, Child; D013694:Temperament