We investigated the effect of monetary rewards on the rate of pain discounting. Our aim, also, was to understand the effect of previous painful dental experiences on the rate of discounting pain. Two groups completed a discounting task. In the first group, delayed pain was weaker than immediate pain, and in the second group delayed pain was stronger than immediate pain. Two conditions were studied: pain was either accompanied by a monetary reward or not. We found that (...) people preferred immediate pain when it was weaker than delayed pain; however, when delayed pain was stronger than immediate pain, there was no clear preference. In both groups the preference for immediate pain was higher when pain was accompanied by a monetary reward. Previous painful experiences were not related to the rate of discounting. It was concluded that the preference for delayed pain depends on the intensity of pain, and it can be modified by rewards that accompany pain. (shrink)

Breaking one's dieting rule or resolution to quit smoking, procrastination, convenient lies, even the failure of entire nations to follow through with plans to cut greenhouse gas emissions or keep a pandemic in check - these phenomena have been discussed by philosophers and behavioural scientists as examples of weakness of will and delay discounting. Despite the common subject matter both fields have to date rarely worked together for mutual benefit. For the empirical literature is hardly accessible to a (...) reader not familiar with econometric theory; and researchers in the behavioural sciences may find philosophical accounts invoking discounting models difficult to understand without inside knowledge of the debates and historical background. -/- Nora Heinzelmann targets this lacuna by making the ideas and findings from both disciplines intelligible to outsiders. This reveals that discounting - as philosophers have conceived of it - is neither necessary nor sufficient for weakness of will, even though there is substantial overlap. Heinzelmann develops a richer descriptive account of weakness of will that is based on the empirically founded assumption that weak-willed behaviour is determined by uncertainty about whether or when a good materialises. She also explains why weakness of the will understood in this way is irrational: the agent yields to a cognitive bias that leads them to underestimate the greater good they think they ought to and can obtain. Finally, she explores practical implications for individuals and policymakers. (shrink)

Humans discount rewards as a function of the delay to their receipt. This tendency is referred to as delay discounting and has been extensively researched in the last decades. The magnitude effect and the trait effect are two phenomena which have been consistently observed for a variety of reward types. Here, we wanted to investigate if these effects also occur in the context of the novel but widespread reward types of Instagram followers and likes and if (...) class='Hi'>delay discounting of these outcomes is related to self-control and Instagram screen time. In a within-subject online experiment, 214 Instagram users chose between smaller, immediate and larger, delayed amounts of hypothetical money, Instagram followers and likes. First, we found that the magnitude effect also applies to Instagram followers and likes. Second, delay discounting of all three reward types was correlated, providing further evidence for a trait influence of delay discounting. Third, no relationships were found between delay discounting and self-control as well as Instagram screen time, respectively. However, a user’s average like count was related to delay discounting of Instagram likes. (shrink)

Income is a primary determinant of social mobility, career progression, and personal happiness. It has been shown to vary with demographic variables like age and education, with more oblique variables such as height, and with behaviors such as delay discounting, i.e., the propensity to devalue future rewards. However, the relative contribution of each these salary-linked variables to income is not known. Further, much of past research has often been underpowered, drawn from populations of convenience, and produced findings that (...) have not always been replicated. Here we tested a large (n = 2,564), heterogeneous sample, and employed a novel analytic approach: using three machine learning algorithms to model the relationship between income and age, gender, height, race, zip code, education, occupation, and discounting. We found that delay discounting is more predictive of income than age, ethnicity, or height. We then used a holdout data set to test the robustness of our findings. We discuss the benefits of our methodological approach, as well as possible explanations and implications for the prominent relationship between delay discounting and income. (shrink)

Intertemporal decision-making is important for both economy and physical health. Nevertheless, in daily life, individuals tend to prefer immediate and smaller rewards to delayed and larger rewards, which is known as delay discounting (DD). Episodic future thinking (EFT) has been proven to influence DD. However, there is still no inconsistent conclusion on the effect of negative EFT on DD. Considering the perceived controllability of negative EFT may address the issue (Controllability refers to the extent to which progress and (...) result of an event could be controlled by ourselves). In the current study, we manipulated EFT conditions (baseline, neutral EFT, negative-controllable EFT and negative-uncontrollable EFT), delayed time (i.e. 1 week, 1 month, 3 months, 6 months, 1 year and 3 years) and reward magnitude (small, large). We mainly found that when experiencing negative-uncontrollable EFT compared to negative-controllable EFT in the delayed time of 6 months with large rewards, individuals chose more delayed rewards, suggesting that negative-uncontrollable EFT effectively reduced DD under conditions of both large-magnitude reward and longer delayed time. The current study provides new insight for healthy groups on optimising EFT. In that case, individuals are able to gain long-term benefits in financial management and healthcare. (shrink)

Delay discounting is a common phenomenon in daily life, which refers to the subjective value of a future reward decreasing as a function of time. Previous studies have identified several cortical regions involved in delay discounting, but the neural network constructed by the cortical regions of delay discounting is less clear. In this study, we employed resting-state functional magnetic resonance imaging (RS-fMRI) to measure the spontaneous neural activity in a large sample of healthy young (...) adults and used the Monetary Choice Questionnaire to directly measure participants’ level of delay discounting. To identify the neural network of delay discounting at rest, we used an individual difference approach to explore brain regions whose spontaneous activities were related to delay discounting across the whole brain. Then, these brain regions served as seeds to identify the neural network of delay discounting. We found that the fractional amplitude of low-frequency fluctuations (fALFF) of the left insula were positively correlated to delay discounting. More importantly, its connectivity to the anterior cingulate cortex was read out for participants’ behavioral performance in the task of delay discounting. In short, our study provides empirical evidence that insula-anterior cingulate cortex connectivity may serve as a part of the neural network for delay discounting. (shrink)

Previous research suggests that exposure to nature may reduce delay discounting and thereby facilitate healthier dietary intake. This pre-registered study examined the impact of online exposure to images of natural scenes on delay discounting and food preferences. It was predicted that exposure to images of natural scenes would be associated with: lower delay discounting; higher desirability for fruits and vegetables ; and delay discounting would mediate the effect of nature-image exposure on food (...) desirability. Adult participants were recruited to an online between-subjects experiment in which they viewed a timed sequence of six images either showing natural landscape scenes or urban scenes. They then completed measures of mood, delay discounting and rated their momentary desire to eat four fruits and vegetables, and four energy-dense foods. There was no statistically significant effect of experimental condition on delay discounting or food desirability. Bayes factors supported the null hypothesis for discounting, and energy-dense food desirability, but provided no strong evidence for either hypothesis for F&V desirability. These findings indicate that brief online exposure to images of nature does not affect momentary impulsivity or energy-dense food preference, whereas for preference for less-energy dense foods, the evidence was inconclusive. (shrink)

The capacity to self-generate mental content that is unrelated to the current environment is a fundamental characteristic of the mind, and the current experiment explored how this experience is related to the decisions that people make in daily life. We examined how task-unrelated thought varies with the length of time participants are willing to wait for an economic reward, as measured using an inter-temporal discounting task. When participants performed a task requiring minimal attention, the greater the amount of time (...) spent engaged in TUT the longer the individual was prepared to wait for an economic reward. These data indicate that self-generated thought engages processes associated with the successful management of long-term goals. Although immersion in the here and now is undeniably advantageous, under appropriate conditions the capacity to let go of the present and consider more pertinent personal goals may have its own rewards. (shrink)

The models of internal self-control that have recently been proposed by behavioral economists do not depict motivational interaction that occurs while temptation is present. Those models that include willpower at all either envision a faculty with a motivation (“strength”) different from the motives that are weighed in the marketplace of choice, or rely on incompatible goals among diverse brain centers. Both assumptions are questionable, but these models’ biggest problem is that they do not let resolutions withstand re-examination while being challenged (...) by impulsive alternatives. The economists’ models all attempt to make a single equilibrium preference predictable from a person’s prior incentives. This was the original purpose of these models’ hyperboloid (“β–δ”) delay discount functions, which have been widely justified by the assumption that a person’s intertemporal inconsistency (impulsiveness) can be accounted for by the arousal of appetite for visceral rewards. Although arousal is clearly a factor in some cases of intertemporal inconsistency, it cannot be blamed for others, and furthermore does not necessarily imply hyperboloid discounting. The inadequacy of β–δ functions is particularly evident in models of internal self-control. I have reviewed several of these models, and have argued for a return to pure hyperbolic discount function as originally proposed, the relatively high tails of which can motivate a recursive process of self-prediction and thereby the formation of self-enforcing intertemporal contracts. Such a process does not require a separately motivated faculty of will, or incompatible goals among brain centers; but it also does not permit the prediction of unique preferences from prior incentives. (shrink)

Recent evidence on intertemporal choice suggests that decision-makers may exhibit both increasing and decreasing impatience simultaneously, called inverse-S discounting. This paper introduces trichotomic discounted utility to model inverse-S discounting. Under trichotomic discounted utility the decision-maker distinguishes between short-term delays, medium-term delays, and long-term delays. Exponential discounting holds within each category, but not necessarily across each category. We provide preference foundations for trichotomic discounted utility in the timed outcomes framework and in the consumption streams framework. The key axiom (...) is a weakening of the time consistency axiom that allows for both increasing and decreasing impatience. We also consider a weak, local version of time consistency, and show that this plausible condition is satisfied only by discount functions with exponential “pieces”. (shrink)

Recent experiments suggest that search direction causally affects the discounted valuation of delayed payoffs. Comparisons between options can increase individuals’ patience toward future payoff options, while searching within options instead promotes impatient choices. We further test the robustness and specificity of this relationship using a novel choice task. Here individuals choose between pairs of delayed payoffs instead of single delayed outcomes. We observe a relationship between search styles and temporal discounting that are the opposite of those previously reported. Integrators (...) – those who tend to compare attributes within alternatives – discount and choose more slowly than comparators – those who are more likely to compare between alternatives. This finding supports and augments the view that individuals’ search strategy is predictive of subsequent discount rates. In particular, the direction of this relationship is further modifiable based on the spatial layout and varying information within an individual’s decision-making environment. (shrink)

Time discounting is the phenomenon that a desired result in the future is perceived as less valuable than the same result now. Economic theories can take this psychological fact into account in several ways. In the economic literature the most widely used type of additive time discounting is exponential discounting. In exponential discounting, the fall of valuation depends by a constant factor on the length of the delay period. It is well known, however, that exponential (...) time discounting often does not describe well how people actually behave. Most people are averse to short delays in gratification now, while their future selves may not mind a bit of extra waiting. This behaviour can be described well by non-exponential discounting functions such as hyperbolic discounting. In hyperbolic discounting, valuations fall rapidly for small delay periods, but the fall gets slower for longer delay periods. Hyperbolic discounting captures phenomena such as procrastination, addiction and in general inconsistency over time. This chapter investigates whether forms of non-exponential discounting, in particular close to the so called Quasi-Hyperbolic model, could also be characterized in terms of dynamically consistent choices when individuals discount the welfare of future selves as well as their payoffs. (shrink)

Temporal discounting is the tendency to devalue temporally distant rewards. Past studies have examined the k-value, the indifference point, and the area under the curve as dependent measures on this task. The current study included these three measures and a fourth measure, called the interest rate total score. The interest rate total score was based on scoring only those items in which the delayed choice should be preferred given the expected return based on simple interest rates. In addition, associations (...) with several individual difference measures were examined including intelligence, executive functions (inhibition, working memory, and set-shifting), thinking dispositions (Need for Cognition and Consideration of Future Consequences) and engagement in substance use and gambling behavior. A staircase temporal discounting task was examined in a sample of 99 university students. Replicating previous studies, temporal discounting increased with longer delays to reward and decreased with higher reward magnitudes. A hyperbolic function accounted for variance in temporal discounting better than an exponential function. Reaction time at the indifference point was significantly longer than at the other choice points. The four dependent measures of temporal discounting were all significantly correlated and were also significantly associated with our individual difference measures. That is, the tendency to wait for a larger delayed reward on all of the temporal discounting measures was associated with higher intelligence, higher executive functions and more consideration of future consequences. Associations between our measures of temporal discounting and outcomes related to substance use and gambling behavior were modest in our university sample. (shrink)

On the basis of literature on delay discounting, potential mechanisms of relations between self-control and altruism are considered. The discussed possibilities are: cause-and-effect relationship, common mechanism, role of intelligence as a factor related both to self-control and altruism, and role of psychological distance. Relations between described perspectives are pointed out, and directions for further research are suggested.

Climate change is projected to have very severe impacts on future generations. Given this, any adequate response to it has to consider the nature of our obligations to future generations. This paper seeks to do that and to relate this to the way that inter-generational justice is often framed by economic analyses of climate change. To do this the paper considers three kinds of considerations that, it has been argued, should guide the kinds of actions that one generation should take (...) if it is to treat both current and future people equitably. In particular it examines the case for what has been termed pure time discounting, growth discounting and opportunity cost discounting; and it assesses their implications for climate policy. It argues that none of these support the claims of those who think they give us reason to delay aggressive mitigation policies. It also finds, however, that the second kind of argument can, in certain circumstances, provide support for passing on some of the costs of mitigation to future generations. (shrink)

Experimental studies suggest that individuals exhibit more risk aversion in choices among prospects when the payment and resolution of uncertainty are immediate relative to when it is delayed. This leads to preference reversals that cannot be attributed to discounting. When data suggest that utility is time-independent, probability weighting functions, such as those used to model prospect theory preferences, can accommodate such reversals. We propose a simple descriptive model with a two-parameter probability weighting function where one of these parameters depends (...) on the time at which a prospect is resolved. The time-dependent parameter is responsible for the curvature of the probability weighting function and is regarded as an index of sensitivity towards changes in probabilities. We provide conditions that characterize increased sensitivity towards more distant probabilities; this can account for the observed relatively less risk aversion towards delayed prospects. In our framework, the discount function is unrestricted, such that the model is compatible with empirical findings of non-constant discounting. In a simple application to bargaining we illustrate when it is advantageous for an individual to advance or delay the bargaining resolution time if an opponent displays increased sensitivity towards probability changes with delay. (shrink)

The Discounting Inventory, originally developed in polish language, allows the measurement of individual differences in the delay, probabilistic, effort, and social discounting rates. The present study attempted to validate the DI’s psychometric properties using German university students and to compare the results to those from a sample of Polish university students. Over four hundred participants completed the DI and traditional discounting measures. A confirmatory factor analyses indicated that the original four-factor model of the DI provided an (...) excellent fit for the German data and internal consistency was high. These outcomes were similar, if not superior, to those from the Polish sample. DI scores strongly correlated with traditional discounting measures scores in both samples, replicating previous results. These findings indicate that the DI is a valid measure for use in a sample from another cultural setting, which is potentially useful to both researchers and practitioners. (shrink)

Ainslie's insightful treatment of dynamically inconsistent choice stands in contrast to traditional views in psychology, economics, and philosophy. We comment on the form of the discounting function and on new findings regarding choice between delayed rewards. Finally, we argue that the positive correlation between temporal and probability discounting is inconsistent with the view that impulsivity represents a unitary trait.

We conduct an experiment to investigate the degree to which deviations from exponential discounting can be accounted for by the hypothesis of hyperbolic discounting. Subjects are asked to choose between an earlier or later payoff in a series of 40 choice questions. Each question consists of a pair of monetary amounts determined by compounding a given base amount at a constant rate per period. Two bases (8 and 20 dollars), three compounding rates (low, medium and high) and three (...) delays (2, 4, and 6 weeks) are each used. There are also 2 initial periods (Today and 2 weeks) and there are two separate questionnaires, one with lower “realistic” compounding rates and the other with higher compounding rates, typical of those used in previous studies. We analyze the detailed patterns of choice in 6 groups of 6 related questions each (in which the base and rate is fixed but the initial period and delay varies), documenting the frequency of patterns consistent with exponential discounting and with hyperbolic discounting. We find that exponential discounting is the clear modal choice pattern in virtually all cases. Hyperbolic discounting is never the modal pattern (except in the sense that constant discounting is a special case of hyperbolic discounting). We also estimate a linear probability model that takes account of individual heterogeneity. The estimates show substantial increases in the probability of choosing the later option when the compounding rate increases, as one would expect. There are small, sometimes significant, increases in this probability when the delay is increased or the initial period is in the future. Such behavior is consistent with hyperbolic discounting, but can account for only a small proportion of choices. Overall, deviations from exponential discounting appear to be due to error, or to other effects not accounted for by hyperbolic discounting. Principal among these is an increase in later choices when the base is larger. (shrink)

Mouse tracking, a new action‐based measure of behavior, has advanced theories of decision making with the notion that cognitive and social decision making is fundamentally dynamic. Implicit in this theory is that people's decision strategies, such as discounting delayed rewards, are stable over task design and that mouse trajectory features correspond to specific segments of decision making. By applying the hierarchical drift diffusion model and the Bayesian delay discounting model, we tested these assumptions. Specifically, we investigated the (...) extent to which the “mouse‐tracking” design of decision‐making tasks (delay discounting task, DDT and stop‐signal task, SST) deviate from the standard “keypress” design of decision making tasks. We found remarkable agreement in delay discounting rates (intertemporal impatience) obtained in the keypress and mouse‐tracking versions of DDT (ρ = 0.90) even though these tasks were given about 1 week apart. Rates of evidence accumulation converged well in the two versions (DDT, ρ =.86; SST, ρ =.55). Omission/commission error in SST showed high agreement (ρ =.42, ρ =.53). Mouse‐motion features such as maximum velocity and AUC (area under the curve) correlated well with nondecision time (ρ = −.42) and boundary separation (ρ =.44)—the amount of information needed to accumulate prior to making a response. These results indicate that the response time (RT) and motion‐based decision tasks converge well at a fundamental level, and that mouse‐tracking features such as AUC and maximum velocity do indicate the degree of decision conflict and impulsivity. (shrink)

Traumatic brain injuries to the frontal lobes are associated with many maladaptive forms of behavior. We investigated the association between brain damage and impulsivity, as measured by the rate of delay discounting. The main aim of this study was to test the hypothesis of steeper discounting of different amounts in a group of patients with frontal lobe damage. We used a delay discounting task in the form of a structured interview. A total of 117 participants (...) were divided into five groups: three neurological groups and two groups without brain damage. Our analyses showed that patients with focal damage to the frontal lobes demonstrated steeper delay discounting than other participants. Other clinical groups demonstrated similar discounting rates. The data pattern related to the magnitude effect on the group level suggested that the magnitude effect is absent in the group of patients with damage to the frontal lobes; however, results were less consistent on an individual level. Amount-dependent discounting was observed in only two groups, the healthy control group and the neurological group with other cortical areas damaged. (shrink)

Recent research introduced the Discounting Inventory that allows the measurement of individual differences in the delay, probabilistic, effort, and social discounting rates. The goal of this investigation was to determine several aspects of the reliability of the Discounting Inventory using the responses of 385 participants. Two types of reliability are of interest. Internal consistency and test-retest stability. A secondary aim was to extend such reliability measures beyond the non-clinical participant. The current study aimed to measure the (...) reliability of the DI in a nicotine-dependent individuals and non-nicotine-dependent individuals. It is concluded that the internal consistency of the DI is excellent, and that the test-retest reliability results suggest that items intended to measure three types of discounting were likely testing trait, rather than state, factors, regardless of whether “non-smokers” were included in, or excluded from, the analyses. With these cautions in mind, however, the psychometric properties of the DI appear to be very good. (shrink)

Under the presupposition that human time perception is distorted in intertemporal choice, this study constructs a time scale in the framework of axiomatic measurement. First, the conditions (homogeneity of degree one or two) to identify the form of a time scale are proposed so that one can determine whether the hyperbolic or exponential is a more suitable function for modeling people’s discounting. Homogeneity of degree one implies that subjective time delay is measured by a power scale and its (...) discount function becomes a power-exponential type, whereas homogeneity of degree two implies that subjective time delay is measured by a log scale and its discount function becomes a hyperbolic type. Second, a method is shown for constructing a model that can reflect subadditive and superadditive discounting. A non-commutative and non-associative concatenation operation is provided to generate a time string consisting of subdivided durations that incorporates the effect of repeated delay with a subdivided duration. The discounting model is yielded by substituting these strings in an exponential model equipped with a generalized time scale, and the determination of subadditivity or superadditivity depends on whether the discount function value of a product by the non-commutative and non-associative operation is, respectively, smaller or greater than that of a product by an operation of the usual extensive structure. (shrink)

We present an experiment in which we add a common delay in a choice between two risky prospects. The results show that delay produces the same change in preferences as in the well-documented common ratio effect in risky lotteries. The added common delay acts as if the probabilities were divided by some common ratio. Moreover, we show that there is a strong magnitude effect, in the sense that the effect of delay depends on the magnitude of (...) the outcome. The results are consistent with the recently introduced probability time trade-off (PTT) model by Baucells and Heukamp. We present a parameterization of the model based on the experimental results, showing that the value function exhibits increasing relative risk aversion, the weighting function is s-shaped, and the intrinsic discount rate is decreasing. (shrink)

This study investigated the differences between past and future temporal discounting in terms of neural activity in relation to temporal distance. Results show that brain regions are engaged differently in past and future temporal discounting. This is likely because past temporal discounting requires memory reconstruction, whereas future temporal discounting requires the processing of uncertainty about the future. In past temporal discounting, neural activity differed only when preferences were made between rewards received one hour prior and (...) rewards received further in the past. The peak amplitudes of P2 and P3 varied as the temporal distance increased from 2 weeks to 50 years. In future temporal discounting, neural activity differed only when preferences were evaluated between two delayed rewards. The delay conditions and had a significant influence on P2 and N2. Findings indicate the existence of different decision-making systems operating in past and future temporal discounting. (shrink)

The concept of behavioural mass provides one avenue for justifying (or making rational) the phenomenon of declining impatience, according to which decision makers put more value on delays that will occur in the near future than on those that will occur later.

How is it conceivable or even psychologically possible that rational agents sometimes appear to act against their own acknowledged self-interest? This issue, commonly known as “weakness of the will”, has contributed to much of our individual and collective failure to address pressing problems even if solutions are well-known and readily available. It has fascinated philosophers since ancient times. Recent advances in psychology, behavioural economics and neuroscience have allowed us to approach the phenomenon from a new perspective. A novel account that (...) draws on empirical research characterises weakness of will as a failure to persist in an intention in the face of temptation. However, contemporary work finds it difficult to determine whether this account should replace or supplement orthodox views. This is partially due to a larger problem: philosophers struggle to understand and conceptually connect the various independent strands of empirical research into self-control, willpower, delay of gratification, ego depletion, implementation intentions, delay discounting, etc. Targeting both issues, the present work advances current research into weakness of will in two ways: first, it raises a novel challenge specific for orthodox accounts in philosophy. More precisely, I argue that they yield absurd results in dilemmas, and I show that this puzzle has repercussions for decision theory and epistemology. Second, my thesis renders econometric and psychological research into delay discounting intelligible to a philosophical readership. More specifically, I explain why standard discounting models fail to capture core cases of weakness of will that are also the object of research in developmental psychology. I thereby rectify rampant myths about preference reversals and discount functions in the philosophical and scientific literature. In short, my dissertation connects empirical and philosophical work into weakness of will conceptually in order to tackle issues in current research and advance our joint understanding of a longstanding and problematic phenomenon. (shrink)

Pickard’s contribution reminds me that conceptualizing choice is no simple matter. Pickard sees choice as entirely voluntary, while I argue that choice is only partially voluntary. Choices are based on appraisals of situations, which fluctuate due to external circumstances and internal states such as emotion and mood. Habit itself competes with volition, and all these parameters vary with development. Psychological factors such as delay discounting and especially one's belief in one's agency are critical for volitional choice as well.