Infant-directed communication in lowland gorillas (Gorilla gorilla): do older animals scaffold communicative competence in infants?
Infant-directed speech is a linguistic phenomenon in which adults adapt their language when addressing infants in order to provide them with more salient linguistic information and aid them in language acquisition. Adult-directed language differs from infant-directed language in various aspects, including speech acoustics, syntax, and semantics. The existence of a "gestural motherese" in interaction with infants, demonstrates that not only spoken language but also nonvocal modes of communication can become adapted when infants are recipients. Rhesus macaques are so far the only nonhuman primates where a similar phenomenon to "motherese" has been discovered: the acoustic spectrum of a particular vocalization of adult females may be altered when the addressees are infants. The present paper describes how gorillas adjust their communicative strategies when directing intentional, nonvocal play signals at infants in the sense of a "nonvocal motherese." Animals of ages above infancy use a higher rate of repetitions and sequences of the tactile sensory modality when negotiating play with infants. This indicates that gorillas employ a strategy of infant-specific communication.
Cluster Languages of Emotion, Department of Education and Psychology, Evolutionary Psychology, Freie Universitaet Berlin, Berlin, Germany. evamaria.luef@fu-berlin.de
Eva Maria
EM
Luef
Katja
K
Liebal
D000819:Animal Communication; D000818:Animals; D005260:Female; D006071:Gorilla gorilla / Q000502:physiology* / Q000523:psychology*; D008425:Maternal Behavior / Q000502:physiology* / Q000523:psychology*; D014741:Video Recording