The effect of “should” and “would” instructions on delay discounting of rewards for self and others

A fragile effect: The influence of episodic memory on delay discounting

Delay discounting occurs when a reward loses value as a function of delay. Episodic future thinking (EFT) reliably decreases delay discounting. EFT may share cognitive features with recalling episodic memories such as constructive episodic simulation. We therefore explored whether recalling episodic memories also reduces delay discounting. In Experiment 1, participants wrote about episodic memories and recalled those memories before completing a delay discounting task. Episodic memories reduced delay discounting according to one commonly used delay discounting measure (area under the curve) but not another (using the hyperbolic model). Experiment 2 compared the effects of general and episodic memories. Neither general nor episodic memories significantly decreased delay discounting compared with a control "counting" condition, but episodic memories reduced delay discounting compared with general memories under some conditions. In Experiment 3, episodic memories did not decrease delay discounting compared with three other control conditions while EFT did. Experiment 3 therefore found that thinking must be both episodic and future orientated to reduce delay discounting. Together, these results suggest that episodic thinking is not sufficient to reliably decrease delay discounting, rather, features unique to episodic future thinking are required. Episodic memory might reduce delay discounting in some contexts, but this effect is small and fragile.

Reduced access to reinforcement drives delay discounting during experienced delays

Rewards lose value as a function of delay. Previous studies suggest that delays have a bigger effect on reward value when people must wait during the delay. However, whether delays involve waiting or postponing has often been confounded with whether choices are about hypothetical or real rewards. The current study characterized the effects of waiting and postponing in hypothetical and experiential choice contexts separately. In Experiment 1 we observed steeper delay discounting for waiting than for postponing in choices about both hypothetical money and about experienced computer game points. Two factors potentially contributing to steeper discounting in choices about waiting are reduced access to other rewards and direct costs of waiting. In Experiment 2, we adapted the experiential delay-discounting task to manipulate each factor separately. Reduced access to other reinforcers had a bigger effect on delay discounting than direct costs of waiting. These results underscore the importance of considering the unique influence of waiting and associated opportunity costs in both basic delay-discounting research and in applied contexts.

Information, ingestion, and impulsivity: The impact of technology-enabled healthy food labels on online grocery shopping in impulsive and non-impulsive consumers

Introduction

Unhealthy food consumption is a problem for society, companies, and consumers. This study aims to contribute to knowledge regarding such issues by investigating how technology-enabled healthy food labels can impact food choice in an online grocery store context. We conceptualized unhealthy and healthy food choice as a matter of impulsivity problems. Three technology-enabled healthy food labels were derived based on variables that might impact self-control, and their influence on food choice was investigated.

Methods

The empirical study consisted of three parts. In the first part, participants’ impulsivity was measured using an adjusting delay task. Part two investigated the effects of self-monitoring, pre-commitment, and social comparison-based technology-enabled healthy food labels on food choice in a hypothetical online grocery shopping setting using a choice-based conjoint experiment. Lastly, in the third part, three where demographical questions were asked.

Results

The results (n = 405) show that self-monitoring, pre-commitment, and social comparison-based technology-enabled healthy food labels had the most to least impact on food choice in that order. Furthermore, the results indicate that self-monitoring and pre-commitment labels had more impact on the choice for impulsive compared to non-impulsive participants. Similarly, the results indicate that social comparison had more impact on choice for non-impulsive participants. These findings suggest that self-monitoring of previous healthy food choices might be more effective than pre-commitment based on discounts for healthy food products. However, these differences were minor.

Discussion

This finding has managerial implications as grocery stores might increase their revenue by introducing self-monitoring labels in an online grocery shopping setting. Future research should investigate these technology-enabled healthy food labels in natural food purchase settings.

Temporal discounting for self and friends in adolescence: A fMRI study

Adolescence is characterized by impulsivity but also by increased importance of friendships. This study took the novel perspective of testing temporal discounting in a fMRI task where choices could affect outcomes for 96 adolescents (aged 10-20-years) themselves and their best friend. Decisions either benefitted themselves (i.e., the Self Immediate - Self Delay' condition) or their friend (i.e., 'Friend Immediate - Friend Delay' condition); or juxtaposed rewards for themselves and their friends (i.e., the 'Self Immediate - Friend Delay' or 'Friend Immediate - Self Delay' conditions). We observed that younger adolescents were more impulsive; and all participants were more impulsive when this was associated with an immediate benefit for friends. Individual differences analyses revealed increased activity in the subgenual anterior cingulate cortex extending in the ventral striatum for immediate relative to delayed reward choices for self. Temporal choices were associated with activity in the prefrontal cortex, parietal cortex, insula, and ventral striatum, but only activity in the right inferior parietal lobe was associated with age. Finally, temporal delay choices for friends relative to self were associated with increased activity in the temporo-parietal junction and precuneus. Overall, this study shows a unique role of the social context in adolescents' temporal decision making.

Choices about whether to wait: Changes in delay discounting without changes in time perception

Delay discounting occurs when the present, subjective value of a reward decreases as a function of delay. Delay discounting is steeper when individuals must wait during the delay, and delay discounting rates for decisions about waiting are not strongly correlated with those for decisions about postponing without waiting. We examined whether changes in delay discounting in choices about waiting are linked to changes in subjective time perception. In Experiment 1, participants completed an experiential waiting task twice. We established that delay discounting was steeper later in the session. In Experiment 2 participants again completed the delay discounting task twice, and we also tracked time perception across the session using the temporal bisection task. Once again, participants demonstrated steeper discounting during the second discounting task, but time perception did not differ significantly. Additionally, discounting rates were not correlated with subjective time perception. Changes in delay discounting across the session might be understood in terms of context or reference effects.

Recently encountered delay lengths produce contrast effects on delay discounting

People demonstrate shallower delay discounting when they have recently made decisions about smaller amounts of money than when they have recently made decisions about larger amounts of money. That is, recent reward amounts produce a contrast effect on delay discounting. We tested whether a similar contrast effect occurs for delays. We recruited two groups of participants via Mechanical Turk. The shorter-delay group made choices about delays ranging from one day to one month, and the longer-delay group made choices about delays ranging from 14 months to 30 years. Both groups then made choices about the same, intermediate delays (one week to 21 months); the longer delay group showed significantly shallower delay discounting, indicating a contrast effect. This suggests that delay discounting is affected not just by absolute delay length, but by the relative delay length.