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.


First International Conference; Italy, 2001

Event Details

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Paper Session #49
Thursday, November 29, 2001
3:00 PM–3:50 PM
Palladian Refectory Hall
Area: EAB
Chair: Carlos F. Aparicio (University of Guadalajara, Mexico)
On Choice Dynamics
Domain: Applied Behavior Analysis
CARLOS F. APARICIO (University of Guadalajara)
Abstract: It has been suggested that under conditions in which the reinforcing environment remains constant for long periods, behavioral adaptation to changes in the reinforcing environment might be slow, whereas when the reinforcing environment changes frequently behavior might change rapidly. These ideas were tested with 24 rats responding in a choice situation that varied the speed of environmental change between and within sessions. For one group (8 rats), a series of seven reinforcer ratios was arranged within each session. The reinforcer ratios were not signaled, but a 1 min black-out was used to signal the start of each new reinforcer ratio. For another group (8 rats) the reinforcing ratio varied from one session to another, each day the rats were exposed to a different reinforcing ratio. Two restrictions applied: a) The reinforcer ratio was randomly selected by the experimenter, and b) no reinforcer ratio operated for two consecutive sessions. The last group (8 rats) was exposed to the same reinforcing ratio for 15 consecutive sessions, after which, a different reinforcing ratio was picked up for the next 15 sessions. This procedure was repeated until the whole series of seven reinforcer ratios was completed. Generally, the results supported the notion that under some conditions behavioral adjustment occurs very rapidly. The implications of these results for a dynamic model of choice were discussed.
Melioration and Optimization as Explanations of Choice Behavior
Domain: Applied Behavior Analysis
MICHAEL B. EHLERT (University of Nevada, Reno)
Abstract: Objective Optimal choice theory permeates most of the natural and social sciences, from Fermat’s principle of least time in physics to fitness maximization in evolutionary biology to utility maximization in economics. Herrnstein and Vaughan (1980) proposed an alternative to optimization, called melioration. Although in most situations melioration and optimization predict the same outcome, some special circumstances allow different outcomes. Operant behavior provides a ready-made experimental setting to test choice behavior. This paper considers multiple experiments that used operant procedures to pit melioration against optimization. Methodology White Carneaux pigeons served as subjects in operant chambers. The pigeons pecked either of two response alternatives to gain access to grain reinforcement based on complex feedback functions. In the initial phases, reinforcement conditions were such that both optimization and melioration predicted identical results. Subsequent phases instituted reinforcement conditions that tested whether optimization or melioration best described choice behavior. Results In the initial phases, the pigeons reliably allocated behavior consistent with both optimization and melioration. Those phases that provided different outcomes for behavior allocation produced results consistent with melioration rather than optimization. Conclusions The results support melioration as the more general explanation of choice behavior.



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