Twinship and psychological differentiation.
D000704:Analysis of Variance; D001828:Body Image; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D009769:Object Attachment; D010465:Perception; D010551:Personality; D011247:Pregnancy; D011386:Projective Techniques; D012649:Self Concept; D012801:Sibling Relations; D014427:Twins