TY - JOUR
T1 - Will travel for food
T2 - Spatial discounting in two New World monkeys
AU - Stevens, Jeffrey R.
AU - Rosati, Alexandra G.
AU - Ross, Kathryn R.
AU - Hauser, Marc D.
N1 - Funding Information:
We are grateful for funding from the National Research Service Award (National Institutes of Health) to J.R.S., the Harvard College Research Program to A.G.R., and an NSF-ROLE grant to M.D.H. We thank Jen Gong, Sarah Heilbronner, Teddy Jones, and Jenny Pegg for assistance in conducting the experiments and Matt Kamen for building the apparatus. We appreciate comments on the manuscript from Fiery Cushman, Sarah Heilbronner, Tim O’Donnell, and three anonymous referees.
PY - 2005/10/25
Y1 - 2005/10/25
N2 - Nonhuman animals steeply discount the future, showing a preference for small, immediate over large, delayed rewards [1-5]. Currently unclear is whether discounting functions depend on context. Here, we examine the effects of spatial context on discounting in cotton-top tamarins (Saguinus oedipus) and common marmosets (Callithrix jacchus), species known to differ in temporal discounting [5]. We presented subjects with a choice between small, nearby rewards and large, distant rewards. Tamarins traveled farther for the large reward than marmosets, attending to the ratio of reward differences rather than their absolute values. This species difference contrasts with performance on a temporal task in which marmosets waited longer than tamarins for the large reward. These comparative data indicate that context influences choice behavior, with the strongest effect seen in marmosets who discounted more steeply over space than over time. These findings parallel details of each species' feeding ecology. Tamarins range over large distances and feed primarily on insects, which requires using quick, impulsive action. Marmosets range over shorter distances than tamarins and feed primarily on tree exudates, a clumped resource that requires patience to wait for sap to exude [6-9]. These results show that discounting functions are context specific, shaped by a history of ecological pressures.
AB - Nonhuman animals steeply discount the future, showing a preference for small, immediate over large, delayed rewards [1-5]. Currently unclear is whether discounting functions depend on context. Here, we examine the effects of spatial context on discounting in cotton-top tamarins (Saguinus oedipus) and common marmosets (Callithrix jacchus), species known to differ in temporal discounting [5]. We presented subjects with a choice between small, nearby rewards and large, distant rewards. Tamarins traveled farther for the large reward than marmosets, attending to the ratio of reward differences rather than their absolute values. This species difference contrasts with performance on a temporal task in which marmosets waited longer than tamarins for the large reward. These comparative data indicate that context influences choice behavior, with the strongest effect seen in marmosets who discounted more steeply over space than over time. These findings parallel details of each species' feeding ecology. Tamarins range over large distances and feed primarily on insects, which requires using quick, impulsive action. Marmosets range over shorter distances than tamarins and feed primarily on tree exudates, a clumped resource that requires patience to wait for sap to exude [6-9]. These results show that discounting functions are context specific, shaped by a history of ecological pressures.
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U2 - 10.1016/j.cub.2005.09.016
DO - 10.1016/j.cub.2005.09.016
M3 - Article
C2 - 16243033
AN - SCOPUS:27144471840
VL - 15
SP - 1855
EP - 1860
JO - Current Biology
JF - Current Biology
SN - 0960-9822
IS - 20
ER -