Hilldale Professor of Psychology and Zoology
Director, Letters and Science Honors Program
Ph.D. 1968, University of Pennsylvania
Our captive colony of cotton-top tamarins closed in 2008 after more than 35 years of research on these cooperatively breeding primates and our group is working on several new directions.
1. Hormonal correlates of relationship quality in human couples (with Denali Lukes)
We found that monogamous pairs of cotton top tamarins had similar levels of the pair-bonding hormone oxytocin and that oxytocin levels were directly correlated with the amount of affiliative and sexual behavior between the mates. Female oxytocin levels were best explained by how much contact and grooming (stroking) they received and male levels by how much sex they had( Snowdon et al. 2010). We are now looking at hormonal levels in human couples and evaluating relationship quality to better understand what leads to good and lasting human relationships.
2. How animals respond to species-specific music (with Megan Savage and David Teie)
We found that tamarins did not respond to emotional aspects of human based music but did react emotionally to music composed in their frequency range and tempo (Snowdon and Teie, 2010). We are now studying how music composed for acts affects their behavior compared to human based music and also whether soothing cat music will reduce separation anxiety.
3. Noninvasive brain imaging and responses to mate and infant cues (with Toni Ziegler)
We pioneered the use of functional magnetic resonance imaging of socially important stimuli in marmosets (Ferris et al. 2001, 2004). Male marmosets change their responsiveness to olfactory cues from novel females when they became fathers and fathers react to infant odors and sounds more than non-fathers do. We are developing ways to image neural activity in response to female and infant cues in males as they go from being single males, to paired, non-fathers to being fathers.
Snowdon, C. T. & Ziegler, T. E. (2007) Growing up cooperatively: Family processes and infant development in marmosets and tamarins. Journal of Developmental Processes 2: 40-66.
De la Torre, S. & Snowdon, C. T. (2009) Dialects in pygmy marmosets? Population variation in call structure, American Journal of Primatology, 71, 333-342.
Snowdon, C. T. (2009) Plasticity of communication in nonhuman primates. Advances in the Study of Behavior, 40, 239-276.
Snowdon, C. T. & Teie, D. (2010) Affective responses in tamarins elicited by species-specific music, Biology Letters,6, 30-32.
Cronin, K. A. Schroeder, K. K. and Snowdon, C. T. (2010). Prosocial behaviour emerges independent of reciprocity in cottontop tamarins. Proceedings of the Royal Society of London, B.
Snowdon, C. T., Pieper, B. A, Boe, C. Y., Cronin, K. A. Kurian, A. V. & Ziegler, T. E. (2010) Variation in oxytocin levels is associated with variation in affiliative behavior in monogamous pairbonded tamarins, Hormones and Behavior,