Animal Cognition

, Volume 17, Issue 2, pp 177–183 | Cite as

Defining reward value by cross-modal scaling

  • Anna H. CaseyEmail author
  • Alan Silberberg
  • Annika Paukner
  • Stephen J. Suomi
Original Paper


Researchers in comparative psychology often use different food rewards in their studies, with food values defined by a pre-experimental preference test. While this technique rank orders food values, it provides limited information about value differences because preferences may reflect not only value differences, but also the degree to which one good may “substitute” for another (e.g., one food may substitute well for another food, but neither substitutes well for water). We propose scaling the value of food pairs by a third food that is less substitutable for either food offered in preference tests (cross-modal scaling). Here, Cebus monkeys chose between four pairwise alternatives: fruits A versus B; cereal amount X versus fruit A and cereal amount Y versus fruit B where X and Y were adjusted to produce indifference between each cereal amount and each fruit; and cereal amounts X versus Y. When choice was between perfect substitutes (different cereal amounts), preferences were nearly absolute; so too when choice was between close substitutes (fruits); however, when choice was between fruits and cereal amounts, preferences were more modest and less likely due to substitutability. These results suggest that scaling between-good value differences in terms of a third, less-substitutable good may be better than simple preference tests in defining between-good value differences.


Choice Reward value Substitutability Cross-modal scaling Economics Monkey 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Anna H. Casey
    • 1
    Email author
  • Alan Silberberg
    • 1
  • Annika Paukner
    • 2
  • Stephen J. Suomi
    • 2
  1. 1.Department of PsychologyAmerican UniversityWashingtonUSA
  2. 2.Eunice Kennedy Shriver National Institute of Child Health and Human DevelopmentPoolesvilleUSA

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