title: Conditions Influencing Vocal Responsiveness of Infant Chimpanzees.
abstract: Infant chimpanzees were tested to determine the effects on distress vocalizations (whimpering, screaming) of stimulus conditions approximating the physical relationship to the mother. Under such conditions spontaneous vocalizations were infrequent, and vocal responsiveness to a painful stimulus was substantially reduced.
authors.forename: W A
authors.initials: WA
authors.lastname: Mason
authors.forename: G
authors.initials: G
authors.lastname: Berkson