Testing temporal frames of colorectal cancer risks: evidence from randomized online experiments.

Low perceived risk of is associated with a low probability of engaging in risk preventive behaviours. Temporal framing has been suggested to make the risk seem higher, as narrower time frames appear to increase perceived risk and intentions to engage in risk-preventive behaviours. In two online experiments, we tested how manipulating risk information about colorectal cancer (CRC) influenced risk perception and preventive behaviours. 902 men and women aged 45-54 were recruited from an English online panel. Study 1 (N = 132) investigated how communicating CRC mortality instead of incidence rates influences risk perception, using both yearly and daily frames. In study 2 (N = 770), CRC incidence was described as occurring yearly, daily or hourly. The primary outcome measures were risk perception, intention to engage in preventive behaviours and whether participants chose to read information about ways to reduce CRC risk or skip it to finish the survey. Study 1 did not find a difference in intentions based on information about the risk of developing vs the risk of dying of CRC. Study 2 found that, while communicating CRC incidence occurring as every day increased information-seeking behaviour compared to every year and every hour (57.4% vs 45.9% vs 45.6%, p = 0.012), individuals in the daily condition were less likely to get all comprehension questions right (69.9% vs 78.2% vs 85.0%, respectively, p = 0.015). Temporal framing had no impact on perceived risk or intentions to engage in risk-reducing behaviours. While manipulating risk information in terms of temporal framing did not increase perceived risk, it may influence people's decision to engage with the information in the first place.

Effectiveness of behavioural economics-based interventions to improve colorectal cancer screening participation: A rapid systematic review of randomised controlled trials.

•We searched PubMed, PsycInfo and EconLit for RCTs that evaluated BE interventions in CRC screening.•We identified 1027 papers for title and abstract review. 30 studies were eligible for the review.•The most frequently tested BE intervention was incentives, followed by default principle and salience.•Default-based interventions were most likely to be effective. Incentives had mixed evidence.•BE remains a promising field of interest in relation to influencing CRC screening behaviours.

Culture and group-functional punishment behaviour.

Humans often 'altruistically' punish non-cooperators in one-shot interactions among genetically unrelated individuals. This poses an evolutionary puzzle because altruistic punishment enforces cooperation norms that benefit the whole group but is costly for the punisher. One key explanation is that punishment follows a social-benefits logic: it is eminently normative and group-functional (drawing on cultural group selection theories). In contrast, mismatch-based deterrence theory argues that punishment serves the individual-level function of deterring mistreatment of oneself and one's allies, hinging upon the evolved human coalitional psychology. We conducted multilateral-cooperation experiments with a sample of Spanish Romani people (Gitanos or Calé) and the non-Gitano majority. The Gitanos represent a unique case study because they rely heavily on close kin-based networks and display a strong ethnic identity. We find that Gitano non-cooperators were not punished by co-ethnics in only-Gitano (ethnically) homogeneous groups but were harshly punished by other Gitanos and by non-Gitanos in ethnically mixed groups. Our findings suggest the existence of culture-specific motives for punishment: Gitanos, especially males, appear to use punishment to protect their ethnic identity, whereas non-Gitanos use punishment to protect a norm of universal cooperation. Only theories that consider normative, group-functional forces underlying punishment behaviour can explain our data.

Testing Enhanced Active Choice to Optimize Acceptance and Participation in a Population-Based Colorectal Cancer Screening Program in Malta.

Opt-out strategies have been shown to improve participation in cancer screening; however, there are ethical concerns regarding the presumed consent. In this study, we tested an alternative opt-in strategy, called: "enhanced active choice," in which the response options summarize the consequences of the decision. The study was conducted as part of the Maltese colorectal cancer screening program, which offers men and women, aged 60-64, a "one-off" fecal immunochemical test (FIT). A total of 8349 individuals were randomly assigned to receive either an invitation letter that featured a standard opt-in strategy (control condition), or an alternative letter with a modified opt-in strategy (enhanced active choice condition). Our primary outcome was participation three months after the invitation was delivered. Additionally, we also compared the proportion who said they wanted to take part in screening. We used multivariable logistic regression for the analysis. Overall, 48.4% (N = 4042) accepted the invitation and 42.4% (N = 3542) did the screening test. While there were no statistically significant differences between the two conditions in terms of acceptance and participation, enhanced active choice did increase acceptance among men by 4.6 percentage points, which translated to a significant increase in participation of 3.4 percentage points. We conclude that enhanced active choice can improve male screening participation. Given the higher risk of CRC in men, as well as their lower participation screening, we believe this to be an important finding.

Testing messages from behavioral economics to improve participation in a population-based colorectal cancer screening program in Cyprus: Results from two randomized controlled trials.

•Behavioral economic-based interventions have been suggested to increase uptake in CRC screening programmes.•This study tested the effectiveness of six behavioral economic-based messages in two field trials.•None of the messages increased screening participation.

Dishonesty is more affected by BMI status than by short-term changes in glucose.

There is evidence that human decision-making is affected by current body energy levels and physiological states. There is less clear evidence linking decision-making to long-term changes in energy, as those associated with obesity. We explore the link between energy, obesity and dishonesty by comparing the behaviour of obese and lean subjects when hungry or sated while playing an anonymous die-under-cup task. Participants performed the task either before or after breakfast. We find that short-term switches in energy have only a mild effect on dishonesty, as only lean females lie less when sated. By contrast, obese subjects lie more than lean subjects in both conditions, and they lie more to avoid the lowest payoff than to get the highest payoff. Our findings suggest that the observed patterns are more likely mediated by factors associated with obesity than by short term energy dynamics, and call for a better integration of the psychological, economic and biological drivers of moral behaviour.

Network Interventions for Changing Physical Activity Behaviour in Preadolescents.

Network interventions can help achieve behavioural change by inducing peer-pressure in the network. However, inducing peer-pressure without considering the structure of the existing social network may render the intervention ineffective or weaker. In a 7-week school-based field experiment using preadolescents' physical activity (PA) as a proxy for estimating behavioural change, we test the hypothesis that boys' and girls' distinct networks are susceptible to different social incentives. We run three different social-rewards schemes, in which classmates' rewards depend on the PA of two friends either reciprocally (directly or indirectly) or collectively. Compared to a random-rewards control, social-rewards schemes had an overall significantly positive effect on PA (51.8% increase), with females being more receptive to the direct reciprocity scheme (76.4%) and males to team (collective) rewards (131.5%). Differences in the sex-specific sub-networks can explain these findings. Network interventions adapted to the network-specific characteristics may constitute a powerful tool for behavioural change.

Improving Medical Decision Making and Health Promotion through Culture-Sensitive Health Communication: An Agenda for Science and Practice.

This review introduces the concept of culture-sensitive health communication. The basic premise is that congruency between the recipient's cultural characteristics and the respective message will increase the communication's effectiveness. Culture-sensitive health communication is therefore defined as the deliberate and evidence-informed adaptation of health communication to the recipients' cultural background in order to increase knowledge and improve preparation for medical decision making and to enhance the persuasiveness of messages in health promotion. To achieve effective health communication in varying cultural contexts, an empirically and theoretically based understanding of culture will be indispensable. We therefore define culture, discuss which evolutionary and structural factors contribute to the development of cultural diversity, and examine how differences are conceptualized as scientific constructs in current models of cultural differences. In addition, we will explicate the implications of cultural differences for psychological theorizing, because common constructs of health behavior theories and decision making, such as attitudes or risk perception, are subject to cultural variation. In terms of communication, we will review both communication strategies and channels that are used to disseminate health messages, and we will discuss the implications of cultural differences for their effectiveness. Finally, we propose an agenda both for science and for practice to advance and apply the evidence base for culture-sensitive health communication. This calls for more interdisciplinary research between science and practice but also between scientific disciplines and between basic and applied research.

Short- and long-run goals in ultimatum bargaining: impatience predicts spite-based behavior.

The ultimatum game (UG) is widely used to study human bargaining behavior and fairness norms. In this game, two players have to agree on how to split a sum of money. The proposer makes an offer, which the responder can accept or reject. If the responder rejects, neither player gets anything. The prevailing view is that, beyond self-interest, the desire to equalize both players' payoffs (i.e., fairness) is the crucial motivation in the UG. Based on this view, previous research suggests that fairness is a short-run oriented motive that conflicts with the long-run goal of self-interest. However, competitive spite, which reflects an antisocial (not norm-based) desire to minimize others' payoffs, can also account for the behavior observed in the UG, and has been linked to short-run, present-oriented aspirations as well. In this paper, we explore the relationship between individuals' intertemporal preferences and their behavior in a citywide dual-role UG experiment (N = 713). We find that impatience (short-run orientation) predicts the rejection of low, "unfair" offers as responder and the proposal of low, "unfair" offers as proposer, which is consistent with spitefulness but inconsistent with fairness motivations. This behavior systematically reduces the payoffs of those who interact with impatient individuals. Thus, impatient individuals appear to be keen to minimize their partners' share of the pie, even at the risk of destroying it. These findings indicate that competitively reducing other's payoffs, rather than fairness (or self-interest), is the short-run goal in ultimatum bargaining.

Fair and unfair punishers coexist in the Ultimatum Game.

In the Ultimatum Game, a proposer suggests how to split a sum of money with a responder. If the responder rejects the proposal, both players get nothing. Rejection of unfair offers is regarded as a form of punishment implemented by fair-minded individuals, who are willing to impose the cooperation norm at a personal cost. However, recent research using other experimental frameworks has observed non-negligible levels of antisocial punishment by competitive, spiteful individuals, which can eventually undermine cooperation. Using two large-scale experiments, this note explores the nature of Ultimatum Game punishers by analyzing their behavior in a Dictator Game. In both studies, the coexistence of two entirely different sub-populations is confirmed: prosocial punishers on the one hand, who behave fairly as dictators, and spiteful (antisocial) punishers on the other, who are totally unfair. The finding has important implications regarding the evolution of cooperation and the behavioral underpinnings of stable social systems.

Serotonin modulates striatal responses to fairness and retaliation in humans.

Humans are willing to incur personal costs to punish others who violate social norms. Such "costly punishment" is an important force for sustaining human cooperation, but the causal neurobiological determinants of punishment decisions remain unclear. Using a combination of behavioral, pharmacological, and neuroimaging techniques, we show that manipulating the serotonin system in humans alters costly punishment decisions by modulating responses to fairness and retaliation in the striatum. Following dietary depletion of the serotonin precursor tryptophan, participants were more likely to punish those who treated them unfairly, and were slower to accept fair exchanges. Neuroimaging data revealed activations in the ventral and dorsal striatum that were associated with fairness and punishment, respectively. Depletion simultaneously reduced ventral striatal responses to fairness and increased dorsal striatal responses during punishment, an effect that predicted its influence on punishment behavior. Finally, we provide behavioral evidence that serotonin modulates specific retaliation, rather than general norm enforcement: depleted participants were more likely to punish unfair behavior directed toward themselves, but not unfair behavior directed toward others. Our findings demonstrate that serotonin modulates social value processing in the striatum, producing context-dependent effects on social behavior.

Patient and impatient punishers of free-riders.

Costly punishment of cheaters who contribute little or nothing to a cooperating group has been extensively studied, as an effective means to enforce cooperation. The prevailing view is that individuals use punishment to retaliate against transgressions of moral standards such as fairness or equity. However, there is much debate regarding the psychological underpinnings of costly punishment. Some authors suggest that costly punishment must be a product of humans' capacity for reasoning, self-control and long-term planning, whereas others argue that it is the result of an impulsive, present-oriented emotional drive. Here, we explore the inter-temporal preferences of punishers in a multilateral cooperation game and show that both interpretations might be right, as we can identify two different types of punishment: punishment of free-riders by cooperators, which is predicted by patience (future orientation); and free-riders' punishment of other free-riders, which is predicted by impatience (present orientation). Therefore, the picture is more complex as punishment by free-riders probably comes not from a reaction against a moral transgression, but instead from a competitive, spiteful drive. Thus, punishment grounded on morals may be related to lasting or delayed psychological incentives, whereas punishment triggered by competitive desires may be linked to short-run aspirations. These results indicate that the individual's time horizon is relevant for the type of social behaviour she opts for. Integrating such differences in inter-temporal preferences and the social behaviour of agents might help to achieve a better understanding of how human cooperation and punishment behaviour has evolved.

Culture and cooperation.

Does the cultural background influence the success with which genetically unrelated individuals cooperate in social dilemma situations? In this paper, we provide an answer by analysing the data of Herrmann et al. (2008a), who studied cooperation and punishment in 16 subject pools from six different world cultures (as classified by Inglehart & Baker (2000)). We use analysis of variance to disentangle the importance of cultural background relative to individual heterogeneity and group-level differences in cooperation. We find that culture has a substantial influence on the extent of cooperation, in addition to individual heterogeneity and group-level differences identified by previous research. The significance of this result is that cultural background has a substantial influence on cooperation in otherwise identical environments. This is particularly true in the presence of punishment opportunities.

Reciprocity, culture and human cooperation: previous insights and a new cross-cultural experiment.

Understanding the proximate and ultimate sources of human cooperation is a fundamental issue in all behavioural sciences. In this paper, we review the experimental evidence on how people solve cooperation problems. Existing studies show without doubt that direct and indirect reciprocity are important determinants of successful cooperation. We also discuss the insights from a large literature on the role of peer punishment in sustaining cooperation. The experiments demonstrate that many people are 'strong reciprocators' who are willing to cooperate and punish others even if there are no gains from future cooperation or any other reputational gains. We document this in new one-shot experiments, which we conducted in four cities in Russia and Switzerland. Our cross-cultural approach allows us furthermore to investigate how the cultural background influences strong reciprocity. Our results show that culture has a strong influence on positive and in especially strong negative reciprocity. In particular, we find large cross-cultural differences in 'antisocial punishment' of pro-social cooperators. Further cross-cultural research and experiments involving different socio-demographic groups document that the antisocial punishment is much more widespread than previously assumed. Understanding antisocial punishment is an important task for future research because antisocial punishment is a strong inhibitor of cooperation.

Antisocial punishment across societies.

We document the widespread existence of antisocial punishment, that is, the sanctioning of people who behave prosocially. Our evidence comes from public goods experiments that we conducted in 16 comparable participant pools around the world. However, there is a huge cross-societal variation. Some participant pools punished the high contributors as much as they punished the low contributors, whereas in others people only punished low contributors. In some participant pools, antisocial punishment was strong enough to remove the cooperation-enhancing effect of punishment. We also show that weak norms of civic cooperation and the weakness of the rule of law in a country are significant predictors of antisocial punishment. Our results show that punishment opportunities are socially beneficial only if complemented by strong social norms of cooperation.