Contents lists available at ScienceDirect Personality and Individual Differences journal homepage: www.elsevier.com/locate/paid The effects of potentially real and hypothetical rewards on effort discounting in a student sample Marta Malesza Department of Psychology, University of Potsdam, Karl-Liebknecht-Str. 24-25, OT Golm, 14476 Potsdam, Germany. ARTICLE INFO Keywords: Effort discounting Hypothetical rewards Potentially real rewards ABSTRACT The primary aim of the present study was to investigate the functional form of discounting of monetary rewards by physical effort in potentially real and hypothetical contexts. Individuals (N = 142) completed the assessments with hypothetical and potentially real effort discounting tasks, and their hypothetical or potentially real con- sequences. The data obtained from the experiment reported here suggest that hypothetical conditions yield patterns of discounting that mirror those for potentially real effort tasks and outcomes. However, this finding also leaves open the possibility that the degree of discounting may change together with the repeated exposure to the consequences of decisions, or the counterbalanced order of hypothetical and potentially real tasks. 1. Introduction Discounting refers to a decrease in the subjective value of an out- come as a specific environmental factor on which a reward or a loss is devalued increases (e.g., Rachlin, 2006; Rachlin, Raineri, & Cross, 1991). The most widely studied process, delay discounting (see Madden & Bickel, 2010) typically refers to the preference for smaller immediate rewards over larger but delayed rewards. The value of the larger reward is said to have been discounted. Of course, the value of a reward de- creases as a function of variables other than time. Apart from the dis- counting of delayed rewards, behavioural psychology also studies effort discounting (the decrease in subjective value of the gain coinciding with the increasing effort needed to gain the reward, see Mitchell, 1999, 2004; Sugiwaka & Okouchi, 2004). In behavioural psychology, clinical applications are seen in cases of effort-discounting procedures, particularly with respect to aberrant motivational states in neurological disorders and depression (Hartmann, Hager, Tobler, & Kaiser, 2013). For example, apathetic patients show a reduction in motivation and less goal-directed behaviour. Given the increased interest in precisely measuring the degree of effort discounting, either across specific sub- populations (e.g., cigarette smokers vs. non-smoking individuals, see, e.g., Mitchell, 1999), or across stages of treatment (e.g., as a measure of the efficacy of treatment, see, e.g., Gold et al. (2013)), it is important to determine whether current procedures for assessing human effort dis- counting are valid. 1.1. Hypothetical and potentially real discounting tasks In the typical effort discounting procedure, individuals make a series of forced-choice decisions regarding preference for a relatively small outcome available without any effort, and a larger outcome available after making a specified effortful task. For example, given a choice between €5 available effortlessly and €80 available after swimming two lengths of a pool, most people choose the effortful outcome. However, as the effortless amount is increased in subsequent questions, most participants eventually “switch” their preference from the larger effortful outcome to the smaller effortless outcome (e.g., at an effortless amount of €60). The point at which the individual switches represents the subjective value of the large reward for that effort (Sugiwaka & Okouchi, 2004). This process is repeated across several effort conditions and this results in a discounting pattern in which the subjective value of the large reward diminishes as the effort required gaining the reward increases (Ostaszewski, Bąbel, & Swebodziński, 2013). Using hypothetical discounting tasks circumvents problems with increased prohibitive costs associated with conducting discounting re- search and delivering some outcomes based on individual choices (Lawyer, Schoepflin, Green, & Jenks, 2011; Madden, Begotka, Raiff,& Kastern, 2003). If time is limited, using hypothetical discounting pro- cedures can save time. Multiple prospect choices may be assessed within a single session, thereby allowing the participants to answer several hundred questions in a typical discounting task. Thus, the re- searcher is able to quickly determine the degree of the discounting rate. Moreover, the use of real rewards significantly limits the magnitude of https://doi.org/10.1016/j.paid.2018.03.030 Received 14 January 2016; Received in revised form 18 February 2018; Accepted 15 March 2018 E-mail address: marta.malesza@gmail.com. Personality and Individual Differences xxx (xxxx) xxx–xxx 0191-8869/ © 2018 Elsevier Ltd. All rights reserved. Please cite this article as: Malesza, M., Personality and Individual Differences (2018), https://doi.org/10.1016/j.paid.2018.03.030