Adam Derenne

Delay Discounting of Different Commodities

ABSTRACT When outcomes are delayed, their value is decreased. Delay discounting is a much-studied topic because it is correlated with certain disorders (e.g., pathological gambling). The present study attempts to determine how people would delay discount a number of different commodities, ranging from money to dating partners to federal education legislation. Participants completed delay discounting tasks pertaining to 5 different commodities, with a different set of 5 commodities for 2 groups. Results showed that different commodities were often discounted differently. Both data sets were also subjected to factor analysis. A 2-factor solution was found for both, suggesting that there are multiple “domains” of commodities. This finding is of interest because it suggests that measuring delay discounting for one commodity within a particular domain of commodities will be predictive of how people discount other commodities within that domain but will not be predictive of how they discount commodities within another domain.

Comparing Delay Discounting Rates When Using the Fill-in-the-Blank and Multiple-Choice Methods

ABSTRACT Several methods have been devised to measure delay discounting. The present study recruited university students to complete a delay-discounting task involving five different outcomes (finding a dating partner, free cigarettes, winning

What 50 Years of Research Tell Us About Pausing Under Ratio Schedules of Reinforcement

100,000, being owed

College Students Discount Money “Won” More Than Money “Owed”

100,000, and obtaining ones ideal body image) that was administered using either the fill-in-the blank (FITB) or multiple-choice (MC) method. Results showed that the different administration methods sometimes produced significantly different rates of discounting, the direction of which differed by outcome. Hyperbolic discounting and the area under the discounting curve were nearly always significantly correlated when the FITB method was used but were never significantly correlated when the MC method was used. Discounting across the five outcomes produced a two-factor solution when the FITB data were factor analyzed. The MC data were described by a one-factor solution. The present results illustrate that procedural variables have a potentially profound impact on delay-discounting data, and generalizing from studies on delay discounting should be done with caution until those variables are fully understood.

Testing the Reliability of Delay Discounting of Ten Commodities Using the Fill-in-the-Blank Method.

Textbooks in learning and behavior commonly describe performance on fixed-ratio schedules as “break and run,” indicating that after reinforcement subjects typically pause and then respond quickly to the next reinforcement. Performance on variable-ratio schedules, on the other hand, is described as steady and fast, with few long pauses. Beginning with Ferster and Skinner’s magnum opus, Schedules of Reinforcement (1957), the literature on pausing under ratio schedules has identified the influences on pausing of numerous important variables, in particular ratio size and reinforcement magnitude. As a result, some previously held assumptions have been called into question. For example, research has shown that the length of the pause is controlled not only by the preceding ratio, as Ferster and Skinner and others had assumed (and as implied by the phrase postreinforcement pause), but by the upcoming ratio as well. Similarly, despite the commonly held belief that ratio pausing is unique to the fixed-ratio schedule, there is evidence that pausing also occurs under variable-ratio schedules. If such widely held beliefs are incorrect, then what about other assumptions? This article selectively examines the literature on pausing under ratio schedules over the past 50 years and concludes that although there may indeed be some common patterns, there are also inconsistencies that await future resolution. Several accounts of pausing under ratio schedules are discussed along with the implications of the literature for human performances, most notably the behaviors termed procrastination.

Quantitative summaries of single-subject studies: What do group comparisons tell us about individual performances?

Evidence in the research literature indicates people may treat “won” money differently than they would their own money. The present study had a sample of 648 college students complete a delay-discounting task that involved the hypothetical monetary amounts of

Delay Discounting and Social Policy Issues

1,000 or

Investigating the Relationship Between the Contingencies That Maintain Gambling and Probability Discounting of Gains and Losses

100,000. Participants were asked repeatedly what amount they would accept immediately rather than waiting a given length of time for the full amount. One group was told these amounts were money they had won; the other group was told that the amounts were money they were owed. Results showed participants discounted money “won” more than money “owed,” indicating that won money was less valued than their own money. These results suggest that researchers who study discounting should be aware that contextual factors may play a role in delay discounting.

Shifts in Postdiscrimination Gradients within a Stimulus Dimension Based on Bilateral Facial Symmetry.

Several measures of delay discounting have been shown to be reliable over periods of up to 3 months. In the present study, 115 participants completed a fill-in-the-blank (FITB) delay-discounting task on sets of 5 different commodities, 12 weeks apart. Results showed that discounting rates were not well described by a hyperbolic function but were significantly correlated across the 12 weeks for all 10 commodities. Discounting, when measured by area under the curve, was significantly correlated across the 12 weeks for 9 of the 10 commodities. Absolute values of both measures of discounting sometimes differed across the two administrations of the task. These results support the reliability of the FITB method but raise a number of issues to consider when choosing a method to study delay discounting.

Weaver mutant mice exhibit long-term learning deficits under several measures of instrumental behavior.

Kollins, Newland, and Critchfield (1999) responded to our comments about their review by arguing that their quantitative summary was not a meta-analysis and should not be criticized in these terms. We reply that regardless of what they call their review, it included confounding effects that make interpretations of the results problematic. Kollins et al. also argued that unexpected findings of the sort they reported can serve as a spur for further research. We reply that the understanding of findings that deviate from existing knowledge may well require empirical investigation. Such endeavors, however, should begin with an evaluation of the review procedures that suggested the existence of the differences. Finally, we emphasize that quantitative summaries of individual data are, in the end, a form of group comparison. The implications of using group methods to clarify individual data deserve frank recognition in discussions of the outcomes.Kollins, Newland, and Critchfield (1999) responded to our comments about their review by arguing that their quantitative summary was not a meta-analysis and should not be criticized in these terms. We reply that regardless of what they call their review, it included confounding effects that make interpretations of the results problematic. Kollins et al. also argued that unexpected findings of the sort they reported can serve as a spur for further research. We reply that the understanding of findings that deviate from existing knowledge may well require empirical investigation. Such endeavors, however, should begin with an evaluation of the review procedures that suggested the existence of the differences. Finally, we emphasize that quantitative summaries of individual data are, in the end, a form of group comparison. The implications of using group methods to clarify individual data deserve frank recognition in discussions of the outcomes. We thank Marshall Dermer for his helpful comments.