Investigating the depletion effect: Self-control does not waiver in capuchin monkeys

Abstract

-The ego-depletion hypothesis states that self-control diminishes over time and with exertion. However, there is mixed evidence among human adult and comparative studies as to whether such depletion occurs. It is an important issue, given that evidence for or against this hypothesis could have implications for remediation efforts with individuals who show high impulsivity and low self-control. In a study of potential depletion effects on selfcontrol, capuchin monkeys were presented with two consecutive self-control tasks back-to-back within sessions. Monkeys first completed the accumulation task, in which they were presented with food items one-by-one until the subject retrieved and ate the accumulating items, at which point no more food would be delivered. This required continual inhibition of food retrieval in the face of an increasingly desirable reward. Then, monkeys completed a food exchange task with exchange combinations that either decreased or increased in food quality. Self-control was required in foregoing eating an immediately available food for a potentially better reward later in the trial. Individual differences in accumulation performance were observed, but no depletion effects were seen in the monkeys' exchange performance. Next, monkeys were presented with task order counterbalanced across individuals. No order effects were observed in the monkeys' performance on either self-control task. Monkeys' exchange performance was not significantly correlated with accumulation performance in either experiment. These results indicate no depletion effects and that these tasks may not be related in terms of underlying mechanisms that support self-control performance, even though at face value both require inhibition of eating available food.Keywords -Self-control; Ego-depletion; Capuchin monkey; Accumulation task; Food exchange; Delay of gratification In many circumstances, individuals are faced with a choice between something fairly good now (e.g., a small amount of money or a small treat) or something better later (e.g., a larger amount of money or a larger treat). In these circumstances, self-control is required to forego the immediate reward so as to instead experience a later, but better reward at a future time. Because mishaps of self-control carry steep consequences in today's society (e.g., drug abuse, addiction, gambling, criminal behavior, and social misfortunes), there is an extensive literature devoted to understanding the mechanisms underlying selfcontrol and the factors that lead to its success for some and its failures for others (e.g., Baumeister,

Impulsivity as a trait in domestic dogs (Canis familiaris): A systematic review and meta-analysis.

“…A review of the construct of impulsivity in human studies corroborates distinct subtypes of impulsivity (Dick et al, 2010). However, a key difference between human and animal work is that, while humans do show correlations between tasks within the subtypes of impulsivity (e.g., impulsive action and impulsive choice), animal works shows that different tasks within a subtype are not necessarily related in birds (Logan et al, 2022), rats (Peterson et al, 2015), or primates (Addessi et al, 2013; Blanchard & Hayden, 2015; Parrish et al, 2018). Indeed, our meta-analysis of performance in A-not-B cup and cylinder tasks (tasks within the impulsive action subtype) showed no correlation across seven studies (Figure 2).…”

Better, Not Just More—Contrast in Qualitative Aspects of Reward Facilitates Impulse Control in Pigs

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Guppies show rapid and lasting inhibition of foraging behaviour

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