The infant's free entry into a new environment.
D000223:Adaptation, Psychological; D005106:Exploratory Behavior; D005260:Female; D006801:Humans; D007223:Infant; D008124:Locomotion; D008297:Male; D009034:Mother-Child Relations; D009769:Object Attachment; D010988:Play and Playthings; D012737:Sex Factors; D014705:Verbal Behavior