title: The peek-a-boo game. A evolution and associated behavior, especially bye-bye and shame expression, sduring the second year.
mesh_terms: D001010:Anxiety, Separation; D002657:Child Development; D002675:Child, Preschool; D005260:Female; D006167:Guilt; D006801:Humans; D007223:Infant; D008297:Male; D010553:Personality Development; D010988:Play and Playthings; D011574:Psychoanalytic Theory; D012649:Self Concept