Animal Cognition

, Volume 12, Issue 1, pp 201–207 | Cite as

Gambling for Gatorade: risk-sensitive decision making for fluid rewards in humans

  • Benjamin Y. Hayden
  • Michael L. Platt
Short Communication


Determining how both humans and animals make decisions in risky situations is a central problem in economics, experimental psychology, behavioral economics, and neurobiology. Typically, humans are risk seeking for gains and risk averse for losses, while animals may display a variety of preferences under risk depending on, amongst other factors, internal state. Such differences in behavior may reflect major cognitive and cultural differences or they may reflect differences in the way risk sensitivity is probed in humans and animals. Notably, in most studies humans make one or a few choices amongst hypothetical or real monetary options, while animals make dozens of repeated choices amongst options offering primary rewards like food or drink. To address this issue, we probed risk-sensitive decision making in human participants using a paradigm modeled on animal studies, in which rewards were either small squirts of Gatorade or small amounts of real money. Possible outcomes and their probabilities were not made explicit in either case. We found that individual patterns of decision making were strikingly similar for both juice and for money, both in overall risk preferences and in trial-to-trial effects of reward outcome on choice. Comparison with decisions made by monkeys for juice in a similar task revealed highly similar gambling styles. These results unite known patterns of risk-sensitive decision making in human and nonhuman primates and suggest that factors such as the way a decision is framed or internal state may underlie observed variation in risk preferences between and within species.


Risk Primary reinforcer Neuroeconomics 



We thank Jason-Flor Sisante for helping to set up the human experimental system. We thank Ashley Nutter and Cameron Martin for collecting the data, and the SROP program at Duke for financial support. Experiments were performed in compliance with the laws of the United States.


  1. Barraclough DJ, Conroy ML, Lee D (2004) Prefrontal cortex and decision making in a mixed-strategy game. Nat Neurosci 7:404–410PubMedCrossRefGoogle Scholar
  2. Brainard DH (1997) The Psychophysics toolbox. Spat Vis 10:433–436PubMedCrossRefGoogle Scholar
  3. Brandstätter E, Gigerenzer G, Hertwig R (2006) The priority heuristic: making choices without trade-offs. Psychol Rev 133:409–432CrossRefGoogle Scholar
  4. Chen M, Lakshminarayanan V, Santos L (2006) How basic are behavioral biases? Evidence from Capuchin monkey trading behavior. J Polit Econ 114:517–537CrossRefGoogle Scholar
  5. Caraco T (1981) Energy budgets, risk and foraging preferences in dark-eyed juncos (Junco hyemalis). Behav Ecol Sociobiol 8:213–217CrossRefGoogle Scholar
  6. Hayden BY, Platt ML (2007) Temporal discounting predicts risk sensitivity in rhesus macaques. Curr Biol 17:49–53PubMedCrossRefGoogle Scholar
  7. Hertwig R, Barron G, Weber EU, Erev I (2004) Decisions from experience and the effect of rare events in risky choice. Psychol Sci 15:534–539PubMedCrossRefGoogle Scholar
  8. Huettel SA, Stowe CJ, Gordon EM, Warner BT, Platt ML (2006) Neural signatures of economic preferences for risk and ambiguity. Neuron 49:765–775PubMedCrossRefGoogle Scholar
  9. Kacelnik A, Bateson M (1996) Risky theories—the effects of variance on foraging decisions. Am Zool 36:402–434Google Scholar
  10. Kahneman D, Tversky A (2000) Choices, values, and frames. Cambridge University Press, CambridgeGoogle Scholar
  11. Knight FH (1921) Risk, uncertainty, and profit. Houghton Mifflin, BostonGoogle Scholar
  12. Kuhberger A, Schulte-Mecklenbeck M, Perner J (1999) The Effects of framing, reflection, probability, and payoff on risk preference in choice tasks. Organ Behav Hum Decis Process 78:204–231PubMedCrossRefGoogle Scholar
  13. Kuhnen CM, Knutson B (2005) The neural basis of financial risk taking. Neuron 47:763–770PubMedCrossRefGoogle Scholar
  14. McCoy AN, Platt ML (2005) Risk-sensitive neurons in macaque posterior cingulate cortex. Nat Neurosci 8:1220–1227PubMedCrossRefGoogle Scholar
  15. Rachlin H, Raineri A, Cross D (1991) Subjective probability and delay. J Exp Anal Behav 55:233–244PubMedCrossRefGoogle Scholar
  16. Rachlin H (2000) The science of self-control. Harvard University Press, CambridgeGoogle Scholar
  17. Reboreda J, Kacelnik A (1991) Risk sensitivity in starlings: variability in food amount and food delay. Behav Ecol 2:301–308CrossRefGoogle Scholar
  18. Samuelson PA (1963) Risk and uncertainty: a fallacy of large numbers. Scientia 98:108–113Google Scholar
  19. Schuck-Paim C, Pompilio L, Kacelnik A (2004) State-dependent decisions cause apparent violations of rationality in animal choice. PLos Biol 2:12CrossRefGoogle Scholar
  20. Shafir S, Wiegmann DD, Smith BH, Real LA (1999) Risk-sensitive foraging: choice behaviour of honeybees in response to variability in volume of reward. Anim Behav 57:1055–1061PubMedCrossRefGoogle Scholar
  21. Stephens DW, Krebs JR (1986) Foraging theory. Princeton University Press, PrincetonGoogle Scholar
  22. Sugrue LP, Corrado GS, Newsome WT (2004) Matching behavior and the representation of value in the parietal cortex. Science 304:1782–1787PubMedCrossRefGoogle Scholar
  23. Sugrue LP, Corrado GS, Newsome WT (2005) Choosing the greater of two goods: neural currencies for valuation and decision making. Nat Rev Neurosci 6:363–375PubMedCrossRefGoogle Scholar
  24. Sutton RS, Barto AG (1998) Reinforcement learning: an introduction. MIT Press, CambridgeGoogle Scholar
  25. Weber EU, Shafir S, Blais AR (2004) Predicting risk sensitivity in humans and lower animals: risk as variance or coefficient of variation. Psychol Rev 111:430–445PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  1. 1.Department of Neurobiology and Center for Neuroeconomic StudiesDuke University School of MedicineDurhamUSA
  2. 2.Center for Cognitive Neuroscience and Department of Evolutionary AnthropologyDuke UniversityDurhamUSA

Personalised recommendations