Silberberg, A., Roma, P.G., Huntsberry, M.E., Warren-Boulton, F.R., Sakagami, T., Ruggiero, A.M. & Suomi, S.J. (2008). On loss aversion in capuchin monkeys. Journal of the Experimental Analysis of Behavior, 89, 145-155.

Chen, Lakshminarayanan, and Santos (2006) claim to show in three choice experiments that monkeys react rationally to price and wealth shocks, but, when faced with gambles, display hallmark, human-like biases that include loss aversion. We present three experiments with monkeys and humans consistent with a reinterpretation of their data that attributes their results not to loss aversion, but to differences between choice alternatives in delay of reinforcement.

Key words: loss aversion, token exchange, reversed contingency, delay of reinforcement, prospect theory, choice, monkeys, humans