Social influences on primate vocal development and communication

Charles T. Snowdon

University of Wisconsin, USA

Most studies of nonhuman primate parallels to human cognition and communication involve studies of the closest relatives of humans- great apes. Another approach is to seek parallels among species that share a similar social organization to many human societies. Cooperatively breeding marmosets and tamarins from the neotropics live in small family groups where all group members are involved in infant care. In marmosets we have documented infant "babbling" parallel to that found in human infants. Infants that vocalize more often develop adult call structure more quickly, and infants learn to use babbling to manipulate behavior of caregivers. Adult marmosets display flexibility in vocal structure adjusting both to environmental or habitat acoustics and to changes in social companions. Cotton-top tamarins share food with infants and produce rapid sequences of the calls adults give upon discovering food. Infants that are involved in more food sharing at an earlier age forage independently sooner and give adult food calls at an earlier age. Some preliminary evidence suggests social transmission of information concerning safe versus toxic foods through vocal and visual signals. These results suggest a rudimentary form of "teaching" of infants both about what food to eat and what calls to use with respect to food.

Snowdon, C. T., & Elowson, A. M. (1999). Pygmy marmosets alter call structure when paired. Ethology, 105, 893-908.

Elowson, A. M., Snowdon, C. T., & Lazaro-Perea, C. (1998). "Babbling" and social context in infant monkeys: Parallel to human infants. Trends in Cognitive Science, 2, 35-43.

Snowdon, C. T. (1999). An empiricist's view of language origins. In B. J. King (Ed.), The Origins of Language: What nonhuman primates can tell us. Santa Fe: SAR Press.

Castro, N. A., & Snowdon, C. T. (in press). Development of vocal responses in infant cotton- top tamarins. Behaviour.

Roush, R. S., & Snowdon, C. T. (1999). The effects of social status on food-associated calling behavior in captive cotton-top tamarins, Animal Behaviour, 58, 1299-1305.

Snowdon, Charles T.

Department of Psychology, University of Wisconsin - Madison

W.J. Brogden Hall, 1202 West Johnson Street, Madison, WI 53706-1696, USA

snowdon@macc.wisc.edu