title: The arrival of a rival: maternal perceptions of toddlers' regressive behaviors after the birth of a sibling.
mesh_terms: D000328:Adult; D002652:Child Behavior; D002675:Child, Preschool / Q000523:psychology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D009034:Mother-Child Relations; D002666:Psychology, Child; D012043:Regression, Psychology; D012801:Sibling Relations; D011795:Surveys and Questionnaires