Association for Behavior Analysis International

The Association for Behavior Analysis International® (ABAI) is a nonprofit membership organization with the mission to contribute to the well-being of society by developing, enhancing, and supporting the growth and vitality of the science of behavior analysis through research, education, and practice.


37th Annual Convention; Denver, CO; 2011

Event Details

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Invited Tutorial #356
CE Offered: PSY/BACB
Delay Discounting by Humans and Other Animals: Does the Species Matter?
Monday, May 30, 2011
10:00 AM–10:50 AM
401/402 (Convention Center)
Area: EAB; Domain: Experimental Analysis
PSY/BACB CE Offered. CE Instructor: Leonard Green, Ph.D.
Chair: Matthew C. Bell (Santa Clara University)
Presenting Authors: : LEONARD GREEN (Washington University)

When rats, pigeons, and people choose between immediate and delayed rewards, the subjective value of the delayed reward decreases as time to its receipt increases. This discounting of the delayed reward is well described in all three species by a hyperboloid function. Interestingly, we have observed a magnitude effect (larger delayed rewards are discounted less steeply than smaller delayed rewards) with humans but not with rats or pigeons. In addition, in humans, if an additional waiting period is added prior to both rewards, thus creating a delay common to both alternatives, rate of discounting decreases as the common delay increases. We examined the effect of adding a common delay on discounting in pigeons. When the signals for the time to the sooner and later alternatives were different, the pigeons (in contrast to humans) showed increases in discounting rate with increases in the common delay. When the signal for the common delay was the same for both alternatives, however, rate of discounting decreased as the common delay increased, a result consistent with that obtained with humans. Taken together, our findings demonstrate profound similarities between delay discounting in humans and pigeons, arguing for the importance of conducting both human and nonhuman research.

LEONARD GREEN (Washington University)
Leonard Green received his BA from the City College of New York and his PhD from the State University of New York at Stony Brook.  After completing post-doctoral research, Green ventured west of the Mississippi (although he thought he was still east of the river) where he is Professor of Psychology at Washington University in St. Louis and Director of Undergraduate Studies.  Green’s research concerns choice and decision-making in rats, pigeons, and people, with a particular interest in self-control and impulsivity.  He is one of the developers of behavioral economics, and is co-author of the book Economic Choice Theory: An Experimental Analysis of Animal Behavior and editor of Advances in Behavioral Economics, the third volume of which is subtitled Substance Use and Abuse.  He has been Editor of the Journal of the Experimental Analysis of Behavior, Associate Editor of the Pavlovian Journal of Biological Science, and Consulting Editor for Behavior and Philosophy.  He serves on the Executive Board of the Society for the Quantitative Analysis of Behavior (SQAB), is a Fellow of the Association for Behavior Analysis International and the Association for Psychological Science, and is President of the Society for the Experimental Analysis of Behavior. 



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