The allocation of operant behavior.

The sunk cost effect is the bias or tendency to persist in a course of action due to prior investments of effort, money or time. At the time of the only review on the sunk cost effect across species (Arkes & Ayton, 1999), research with nonhuman animals had been ecological in its nature, and the findings about the effect of past investments on current choice were inconclusive. However, in the last decade a new line of experimental laboratory-based research has emerged with the promise of revolutionizing the way we approach the study of the sunk cost effect in nonhumans. In the present review we challenge Arkes and Ayton's conclusion that the sunk cost effect is exclusive to humans, and describe evidence for the sunk cost effect in nonhuman animals. By doing so, we also challenge the current explanations for the sunk cost effect in humans, as they are not applicable to nonhumans. We argue that a unified theory is called for, because different independent variables, in particular, investment amount, have the same influence on the sunk cost effect across species. Finally, we suggest possible psychological mechanisms shared across different species, contrast and depreciation, that could explain the sunk cost effect.

Section: The Sunk Cost Effect In Nonhuman Animals: Laboratory Studiesmentioning

confidence: 99%

The sunk cost effect across species: A review of persistence in a course of action due to prior investment

Magalhães

White

2016

“…Initial‐link responding provides access to one of two mutually exclusive terminal links. The ratio or proportion of responses in the initial link provides a direct behavioral measure of preference for terminal‐link outcomes (Fantino, ; Grace & Hucks, ; Herrnstein, ). Two technical features of the present concurrent‐chains procedure are important.…”

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confidence: 99%

Preference Reversal Between Impulsive and Self‐control Choice

Beeby

White

2013

In a concurrent-chains procedure, pigeons chose between reinforcers varying in delay and amount. Reinforcer amount was determined by duration of access to grain, and delay was determined by fixed-interval schedules in the terminal links. Preference was measured by the ratio of responses in initial links. Dependent scheduling of variable-interval schedules in initial links ensured that delay and amount were not confounded with frequency of outcomes, which remained equal for the two choices. In Experiment 1, in components signaled by red keys in the initial links, small and large reinforcers were delivered after delays of 1 s and 10 s respectively. In components signaled by green, additional time was added to both delays. Smaller-sooner reinforcers were preferred in red components. In green components, smaller-sooner reinforcers were preferred at short delays, and choices for the larger-later reinforcer generally increased with increasing duration of the added delay. At longer delays, up to 15 s, the larger-later reinforcer was preferred. That is, the pigeons showed within-session preference reversal, with impulsive choice at short delays in red components and self-control choice at long delays in green components. In Experiment 2, added delay to both reinforcement and reinforcer amount were varied. Sensitivity of initial-link response ratios to ratios of amount increased with increasing duration of the added delay. This interaction between delay and amount was predicted if the temporal discounting functions assumed the magnitude effect in which discounting rate was inversely proportional to amount. It was also predicted by the contextual choice model of performance in concurrent-chains procedures.

“…This Generalized Matching Law (GML) has been shown to accurately describe a wide range of choice data at the individual‐subject level in a number of species (see review by Grace & Hucks, ). The IFD can be similarly expressed in generalized form (Bell & Baum, ; Fagen, ; Kennedy & Gray, ):

log (\frac{N_{1}}{N_{2}}) = s . log (\frac{R_{1}}{R_{2}}) + log b,

where N 1 and N 2 are the number of foragers observed at Patch 1 and 2, respectively, R 1 and R 2 are the total reinforcers (or resources) delivered at Patch 1 and Patch 2, s has been conceptualized as either the sensitivity of the group to the resource distribution (Kennedy & Gray, ) or the inverse of the level of interference (Sutherland, ; Fagen, ), and b is the site bias (Bell & Baum, ; Kennedy & Gray, ).…”

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confidence: 99%

“…The sensitivity of behavior to reinforcement is represented by s (the slope of the resulting linear function) and b represents bias towards one patch or another (corresponds to the y-intercept of the function). This Generalized Matching Law (GML) has been shown to accurately describe a wide range of choice data at the individual-subject level in a number of species (see review by Grace & Hucks, 2013). The IFD can be similarly expressed in generalized form (Bell & Baum, 2002;Fagen, 1987;Kennedy & Gray, 1993):…”

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confidence: 99%

Effects of predictability and competition on group and individual choice in a free‐ranging foraging environment

Tan

Sosa

Talbot

et al. 2014

The present study examined the social foraging of rats in an open arena. The relative quantity of food varied across two food sources, or "patches." Five food quantity ratios (1:1, 1:2, 1:8, 8:1, 2:1) were presented in a series of 30-min sessions. Ratios varied randomly across 6-min components within sessions (Phase 1), or in a consistent order across sessions (Phase 2). Group and individual preferences were well described by the ideal free distribution and the generalized matching law, respectively, with evidence of undermatching at both group and individual levels. Sensitivity of individual and collective behavior to the relative quantities of food was higher in Phase 2 than in Phase 1. Competitiveness rankings, assessed before and after experimental sessions by delivering food in rapid succession from a single feeder, was positively related to sensitivity values in Phase 1, but less consistently so in Phase 2. This study illustrates a promising experimental method for investigating foraging in a social context.