Intertemporal prosocial behavior: a review and research agenda.

Research on intertemporal and prosocial decisions has largely developed in separate strands of literature. However, many of the decisions we make occur at the intersection of these two dimensions (intertemporal and prosocial). Trust is an example, where a decision today is made with the expectation that another person will reciprocate (or betray) later. A new literature is emerging to explore the role of time in these types of situations, where time and social considerations are intertwined. In many cases, time introduces (or magnifies) an element of uncertainty about future outcomes and utility that people need to deal with - what will happen, how good will it be, how will it feel. We review this emerging literature on intertemporal prosocial decision-making and discuss how new research can fill existing knowledge gaps.

Ghrelin decreases sensitivity to negative feedback and increases prediction-error related caudate activity in humans, a randomized controlled trial.

The stomach-derived hormone ghrelin plays not only a role in feeding, starvation, and survival, but it has been suggested to also be involved in the stress response, in neuropsychiatric conditions, and in alcohol and drug use disorders. Mechanisms related to reward processing might mediate ghrelin's broader effects on complex behaviors, as indicated by animal studies and mostly correlative human studies. Here, using a within-subject double-blind placebo-controlled design with intravenous ghrelin infusion in healthy volunteers (n = 30), we tested whether ghrelin alters sensitivity to reward and punishment in a reward learning task. Parameters were derived from a computational model of participants' task behavior. The reversal learning task with monetary rewards was performed during functional brain imaging to investigate ghrelin effects on brain signals related to reward prediction errors. Compared to placebo, ghrelin decreased punishment sensitivity (t = -2.448, p = 0.021), while reward sensitivity was unaltered (t = 0.8, p = 0.43). We furthermore found increased prediction-error related activity in the dorsal striatum during ghrelin administration (region of interest analysis: t-values ≥ 4.21, p-values ≤ 0.044). Our results support a role for ghrelin in reward processing that extends beyond food-related rewards. Reduced sensitivity to negative outcomes and increased processing of prediction errors may be beneficial for food foraging when hungry but could also relate to increased risk taking and impulsivity in the broader context of addictive behaviors.

The effect of fast and slow decision-making on equity-efficiency tradeoffs and moral repugnance.

Fast-and-slow models of decision-making are commonly invoked to explain economic behaviour. However, past research has focused on human cooperation and generosity and thus largely overlooked situations where there are sharp conflicts between efficiency and equality, or between efficiency and more intuitive moral values (repugnance). Here, we contribute to fill this gap in the literature. We conducted a preregistered experiment (n = 1500 recruited from Prolific) to assess the effects of fast, intuitive decisions, under time pressure versus slow, deliberate decisions, under time delay, on (i) people's distributional preferences and (ii) their attitudes toward repugnant transactions. The results show increased preference for equality and decreased preference for efficiency under time pressure, but no effects on moral repugnance. Exploratory analyses revealed that most of the observed treatment effects in our data were accounted for by women. Our results provide some support for theories that associate controlled cognition with concern for efficiency, and intuitive, emotional responses with inequality aversion.

A randomized controlled experimental medicine study of ghrelin in value-based decision making.

BACKGROUNDThe stomach-derived hormone ghrelin stimulates appetite, but the ghrelin receptor is also expressed in brain circuits involved in motivation and reward. We examined ghrelin effects on decision making beyond food or drug reward using monetary rewards.METHODSThirty participants (50% women and 50% men) underwent 2 fMRI scans while receiving i.v. ghrelin or saline in a randomized counterbalanced order.RESULTSStriatal representations of reward anticipation were unaffected by ghrelin, while activity during anticipation of losses was attenuated. Temporal discounting rates of monetary reward were lower overall in the ghrelin condition, an effect driven by women. Discounting rates were inversely correlated with neural activity in a large cluster within the left parietal lobule that included the angular gyrus. Activity in an overlapping cluster was related to behavioral choices and was suppressed by ghrelin.CONCLUSIONThis is, to our knowledge, the first human study to extend the understanding of ghrelin's significance beyond the canonical feeding domain or in relation to addictive substances. Contrary to our hypothesis, we found that ghrelin did not affect sensitivity to monetary reward anticipation, but rather resulted in attenuated loss aversion and lower discounting rates for these rewards. Ghrelin may cause a motivational shift toward caloric reward rather than globally promoting the value of reward.TRIAL REGISTRATIONEudraCT 2018-004829-82.FUNDINGSwedish Research Council (2013-07434), Marcus and Marianne Wallenberg foundation (2014.0187) and National Institute on Drug Abuse/National Institute on Alcohol Abuse and Alcoholism Intramural Research Program.

Voting and (im)moral behavior.

Due to diffusion of responsibility, majority voting may induce immoral and selfish behavior because voters are rarely solely responsible for the outcome. Across three behavioral experiments (two preregistered; n = 1983), we test this hypothesis in situations where there is a conflict between morality and material self-interest. Participants were randomly assigned to make decisions about extracting money from a charity either in an experimental referendum or individually. We find no evidence that voting induces immoral behavior. Neither do we find that people self-servingly distort their beliefs about their responsibility for the outcome when they vote. If anything, the results suggest that voting makes people less immoral.

COVID-19 and Politically Motivated Reasoning.

BACKGROUND: During the COVID-19 pandemic, the world witnessed a partisan segregation of beliefs toward the global health crisis and its management. Politically motivated reasoning, the tendency to interpret information in accordance with individual motives to protect valued beliefs rather than objectively considering the facts, could represent a key process involved in the polarization of attitudes. The objective of this study was to explore politically motivated reasoning when participants assess information regarding COVID-19. DESIGN: We carried out a preregistered online experiment using a diverse sample (N = 1,500) from the United States. Both Republicans and Democrats assessed the same COVID-19-related information about the health effects of lockdowns, social distancing, vaccination, hydroxychloroquine, and wearing face masks. RESULTS: At odds with our prestated hypothesis, we found no evidence in line with politically motivated reasoning when interpreting numerical information about COVID-19. Moreover, we found no evidence supporting the idea that numeric ability or cognitive sophistication bolster politically motivated reasoning in the case of COVID-19. Instead, our findings suggest that participants base their assessment on prior beliefs of the matter. CONCLUSIONS: Our findings suggest that politically polarized attitudes toward COVID-19 are more likely to be driven by lack of reasoning than politically motivated reasoning-a finding that opens potential avenues for combating political polarization about important health care topics. HIGHLIGHTS: Participants assessed numerical information regarding the effect of different COVID-19 policies.We found no evidence in line with politically motivated reasoning when interpreting numerical information about COVID-19.Participants tend to base their assessment of COVID-19-related facts on prior beliefs of the matter.Politically polarized attitudes toward COVID-19 are more a result of lack of thinking than partisanship.

Acute effects of alcohol on social and personal decision making.

Social drinking is common, but it is unclear how moderate levels of alcohol influence decision making. Most prior studies have focused on adverse long-term effects on cognitive and executive function in people with alcohol use disorders (AUD). Some studies have investigated the acute effects of alcohol on decision making in healthy people, but have predominantly used small samples and focused on a narrow selection of tasks related to personal decision making, e.g., delay or probability discounting. Here, we conducted a large (n = 264), preregistered randomized placebo-controlled study (RCT) using a parallel group design, to systematically assess the acute effects of alcohol on measures of decision making in both personal and social domains. We found a robust effect of a 0.6 g/kg dose of alcohol on both moral judgment and altruistic behavior, but no effects on several measures of risk taking or waiting impulsivity. These findings suggest that alcohol at low to moderate doses selectively moderates decision making in the social domain, and promotes utilitarian decisions over those dictated by rule-based ethical principles (deontological). This is consistent with existing theory that emphasizes the dual roles of shortsighted information processing and salient social cues in shaping decisions made under the influence of alcohol. A better understanding of these effects is important to understand altered social functioning during alcohol intoxication.

A preregistered replication of motivated numeracy.

Motivated numeracy refers to the idea that people with high reasoning capacity will use that capacity selectively to process information in a manner that protects their own valued beliefs. This concept was introduced in a now classic article by Kahan, Peters, Dawson, & Slovic [2017, Behavioral Public Policy 1, 54-86], who used numeracy to index reasoning capacity, and demonstrated that the tendency to engage in ideologically congruent interpretation of facts increased substantially with people's numeracy. Despite the importance of this finding, both from a theoretical and practical point of view, there is yet no consensus in the literature about the factual strength of motivated numeracy. We therefore conducted a large-scale replication of Kahan, Peters, Dawson, and Slovic (2017), using a pre-specified analysis plan with strict evaluation criteria. We did not find good evidence for motivated numeracy; there are distinct patterns in our data at odds with the core predictions of the theory, most notably (i) there is ideologically congruent responding that is not moderated by numeracy, and (ii) when there is moderation, ideologically congruent responding occurs only at the highest levels of numeracy. Our findings suggest that the cumulative evidence for motivated numeracy is weaker than previously thought, and that caution is warranted when this feature of human cognition is leveraged to improve science communication on contested topics such as climate change or immigration.

Differences in Physical Demands Among Offensive and Defensive Players in Elite Men Bandy.

Purpose: This study examined the physiological sport-specific demands (total distance, mean velocity, effective game time, and time in five velocity zones) in elite bandy players of offensive and defensive playing positions. Method: Data were collected with 10 Hz GPS-units in the Swedish Elite League during the season 2015/16. Ten male elite bandy players were examined during 13 matches. Data were analyzed with Independent Samples Test and with descriptive statistics. Result: Analysis showed that defensive positions covered a significantly longer (p < .001) total distance (23.2 ± 2.4 km vs 21.1 ± 3.5 km) compared to the offensive positions. Significantly higher (p < .001) mean velocity was found in offensive positions (17.8 ± 1.0 km/h vs 15.5 ± 1.6 km/h) in relation to defensive positions. In variable effective game time analysis exposed significant differences (p < .001) between offensive positions and defensive positions (90.4 ± 3.5 min vs 71.3 ± 11.9 min). Furthermore, in easy and moderate skating defensive positions spent significantly (p < .001) more time and in fast, very fast, and sprint skating offensive positions spent significantly (p < .001) more time in relation to each other. The descriptive analysis of positions indicates that libero, defender, and half have the longest game time, half skate the longest distance, and forward have the highest mean velocity during the game. Conclusion: From a practical perspective, the result can provide coaches knowledge when planning the setup in training drills. Thus, the training sessions could be more specific to the playing position, which could maximize the player's physiological outcome in order to optimize performance.

Using quantitative trait in adults with ADHD to test predictions of dual-process theory.

Dual-process theory is a widely utilized modelling tool in the behavioral sciences. It conceptualizes decision-making as an interaction between two types of cognitive processes, some of them fast and intuitive, others slow and reflective. We make a novel contribution to this literature by exploring differences between adults with clinically diagnosed ADHD and healthy controls for a wide range of behaviors. Given the clinical picture and nature of ADHD symptoms, we had a strong a priori reason to expect differences in intuitive vs reflective processing; and thus an unusually strong case for testing the predictions of dual-process theory. We found mixed results, with overall weaker effects than expected, except for risk taking, where individuals with ADHD showed increased domain sensitivity for gains vs losses. Some of our predictions were supported by the data but other patterns are more difficult to reconcile with theory. On balance, our results provide only limited empirical support for using dual-process theory to understand basic social and economic decision-making.

Variation in the µ-Opioid Receptor Gene (OPRM1) Does Not Moderate Social-Rejection Sensitivity in Humans.

Given previous findings from animal studies and small-scale studies in humans, variation in the µ-opioid receptor gene (OPRM1) has been proposed as a strong biological candidate for moderating sensitivity to social rejection. Using a substantially larger sample (N = 490) than previous studies, a prospective genotyping strategy, and preregistered analysis plans, we tested the hypotheses that OPRM1 variation measured by the functional A118G polymorphism (rs1799971) moderates (a) dispositional sensitivity to rejection and feelings of distress following social exclusion and (b) decision making involving social cognition. In three experimental tasks commonly used to assess altruism, reciprocity, and trust in humans, we found no evidence in favor of the hypotheses; nine main tests were preregistered, and all of them yielded small and statistically insignificant estimates. In secondary analyses, we used Bayesian inference and estimation to quantify support for our findings. Taken together, our results strongly suggest that the link between OPRM1 A118G variation and social-rejection sensitivity is weaker than previously thought.

Discrepancy between Health Care Rationing at the Bedside and Policy Level.

BACKGROUND: Whether doctors at the bedside level should be engaged in health care rationing is a controversial topic that has spurred much debate. From an empirical point of view, a key issue is whether there exists a behavioral difference between rationing at the bedside and policy level. Psychological theory suggests that we should indeed expect such a difference, but existing empirical evidence is inconclusive. OBJECTIVE: To explore whether rationing decisions taken at the bedside level are different from rationing decisions taken at the policy level. METHOD: Behavioral experiment where participants ( n = 573) made rationing decisions in hypothetical scenarios. Participants (medical and nonmedical students) were randomly assigned to either a bedside or a policy condition. Each scenario involved 1 decision, concerning either a life-saving medical treatment or a quality-of-life improving treatment. All scenarios were identical across the bedside and policy condition except for the level of decision making. RESULTS: We found a discrepancy between health care rationing at policy and bedside level for scenarios involving life-saving decisions, where subjects rationed treatments to a greater extent at the policy level compared to bedside level (35.6% v. 29.3%, P = 0.001). Medical students were more likely to ration care compared to nonmedical students. Follow-up questions showed that bedside rationing was more emotionally burdensome than rationing at the policy level, indicating that psychological factors likely play a key role in explaining the observed behavioral differences. We found no difference in rationing between bedside and policy level for quality-of-life improving treatments (54.6% v. 55.7%, P = 0.507). CONCLUSIONS: Our results indicate a robust "bedside effect" in the life-saving domain of health care rationing decisions, thereby adding new insights to the understanding of the malleability of preferences related to resource allocation.

Attosecond probe of valence-electron wave packets by subcycle sculpted laser fields.

We experimentally and theoretically demonstrate a self-referenced wave-function retrieval of a valence-electron wave packet during its creation by strong-field ionization with a sculpted laser field. Key is the control over interferences arising at different time scales. Our work shows that the measurement of subcycle electron wave-packet interference patterns can serve as a tool to retrieve the structure and dynamics of the valence-electron cloud in atoms on a sub-10-as time scale.