title: Attachment behavior in thirteen-month-old, opposite-sex twins.
mesh_terms: D000367:Age Factors; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008425:Maternal Behavior; D008426:Maternal Deprivation; D009034:Mother-Child Relations; D009769:Object Attachment; D010988:Play and Playthings; D011247:Pregnancy; D012737:Sex Factors; D012951:Socialization; D013315:Stress, Psychological; D014427:Twins