Intuitions and deliberated strong reciprocity explain

cooperation in maintenance and provision dilemmas

with Simon Gächter, John Maule & Chris Starmer

[Under Review]

While cooperation in one-shot anonymous social dilemma interactions has often been viewed as requiring mental effort for curbing selfish heuristics, a prominent theory posited that deliberation weakens cooperation when heuristics are prosocial. The predictions of these dual-process accounts of cooperation have never been compared in a generalized test that simultaneously manipulates cognitive processes (intuitive vs. deliberated) and social heuristics (selfish vs. prosocial). As our testbed, we use two formally equivalent dilemmas that induce contrasting heuristics, selfish in the maintenance and prosocial in the provisioning of a public good. In two preregistered studies that use time-limit manipulations (n=3653), we show that deliberation promotes cooperation when heuristics are selfish (i.e., in the maintenance dilemma) but not when they are prosocial (i.e., in the provision dilemma). Organizing conflicting findings in the literature, our generalized test shows that the effect of deliberation on cooperation depends on social heuristics, indicating a strong preference for reciprocity.


​​​Is Religious Cooperation Intuitively Parochial?

with Onurcan Yilmaz & John Maule

Nature Human Behavior

[Registered report, Stage 1 acceptance]

Wide-spread evidence indicates that religious belief promotes cooperation through various psychosocial mechanisms. Religions can directly motivate cooperation by instilling altruistic motives or fear of punishment. The consequent increase in trust among religious believers can further support reciprocal cooperation. However, religions can also be divisive. In particular,  public displays of religious identity, while signaling cooperativeness and trustworthiness, provide a mechanism for the systematic discrimination of out-groups such as atheists. Although widespread religious judgmental biases, including distrust towards atheists, have recently been reported and linked to intuitive associations, it remains to be studied whether intuitive religious prejudices induce discrimination in actual cooperation behavior. We study these questions by testing the social heuristics hypothesis (SHH) in a one-shot prisoner’s dilemma game, which predicts that intuitive decisions, reflecting background social experiences, tend to be more cooperative than deliberated decisions. We further explore the implications of an alternative dual-process account of cooperation, the self-control account (SCA), which instead suggests that spontaneous decisions may be viscerally selfish and that controlling these urges require cognitive effort. We plan to increase reliance on intuitive decisions using time-pressure and compare these to relatively more deliberated decisions induced by time-delay. Christian believers who regularly participate in public rituals will be paired in the prisoner’s dilemma either with a practicing Christian or with an atheist. While accumulated evidence for SHH indicates that intuitive cooperation is general (i.e., independent of religious group identity), suggestive evidence for SCA implies that intuitive cooperation may be parochial. 


Is intuition really cooperative? Improved tests support the social heuristics hypothesis 

with John Maule & Chris Starmer

PLoS ONE 13(1): e0190560, January 2018.

Understanding human cooperation is a major scientific challenge. While cooperation is typically explained with reference to individual preferences, a recent cognitive process view hypothesized that cooperation is regulated by socially acquired heuristics. Evidence for the social heuristics hypothesis rests on experiments showing that time-pressure promotes cooperation, a result that can be interpreted as demonstrating that intuition promotes cooperation. This interpretation, however, is highly contested because of two potential confounds. First, in pivotal studies compliance with time-limits is low and, crucially, evidence shows intuitive cooperation only when noncompliant participants are excluded. The inconsistency of test results has led to the currently unresolved controversy regarding whether or not noncompliant subjects should be included in the analysis. Second, many studies show high levels of social dilemma misunderstanding, leading to speculation that asymmetries in understanding might explain patterns that are otherwise interpreted as intuitive cooperation. We present evidence from an experiment that employs an improved time-pressure protocol with new features designed to induce high levels of compliance and clear tests of understanding. Our study resolves the noncompliance issue, shows that misunderstanding does not confound tests of intuitive cooperation, and provides the first independent experimental evidence for intuitive cooperation in a social dilemma using time-pressure.



Dr. Ozan Isler

Experimental and Behavioral Economist

The description – experience gap in cooperation 

with Orestis Kopsacheilis & Dennie van Dolder

[In Progress]

A prominent explanation why people cooperate in social dilemmas is a preference for conditional cooperation—the willingness to cooperate provided the belief that others will likely do the same. The information about the environment that is used to form such beliefs may be acquired in different formats. Research on individual risky decisions, the Description – Experience (DE) gap, shows that beliefs depend on the format of information acquisition: in particular, when information is acquired descriptively (e.g., as aggregate statistics presented in numerical form) people behave as if overweighting rare events whereas, when it is acquired experientially (e.g., as a sequence of individual observations) they behave as if underweighting rare events. However, little is known how information acquisition affects beliefs in social dilemmas. We present a modified Prisoner's Dilemma game to investigate this question. The game allows us to systematically manipulate participants’ beliefs about the cooperativeness of the social environment either through statistical description or experiential sampling. In a large-scale experiment (n = 1006), we find evidence for a DE gap in the social dilemma setting. However, the direction of the social DE gap is the opposite of the individual context: rare uncooperative events have more positive influence on decisions to cooperate in Experience than in Description. Analysis suggests that ambiguity reduces sensitivity towards information regarding the social environment. Consistent with this interpretation, the preference for conditional cooperation is significantly weaker in decisions from experience than from description. 

​​Individual identification of dishonesty

Economic and psychological determinants

with Simon Gächter

[In Progress]

We present a modified mind-game to provide insights into the extrinsic determinants and intrinsic correlates of honesty (n = 3633). In each round of our online game, the participant is first asked to think of a number between 0 and 9, then shown a single-digit random number, and finally asked to report whether the two numbers match. We discuss three sets of results: 1) In line with the literature, we find significant relative stake effects and no absolute stake effects when varying the incentives for being dishonest; 2) Despite becoming more detectable, dishonesty significantly increases with the repetition of rounds, which can be attributed both to poor understanding of the probability distribution of honest matches as well as to justified dishonesty; 3) We identify dishonesty at the individual level by repeating the game up to forty rounds, allowing estimation of psychometric differences between clearly honest and dishonest participants. In a further novel result, we find honesty and cooperation to be significantly related: In particular, we show that participants who are categorized as honest in the mind-game are more likely to be categorized as cooperative in a social dilemma.


Do religious primes decrease selfishness?

Direct replication of Shariff and Norenzayan (2007)

with Onurcan Yilmaz & John Maule

[Under Review]

In an influential article, Shariff and Norenzayan (2007) found that implicit religious and secular primes decrease selfishness in a dictator game, and argued that religion promotes altruism. These findings had significant impact on various fields of study, including numerous theoretical and empirical applications in Moral Psychology. However, replicability of implicit priming studies has recently been seriously questioned, and several recent attempts failed to replicate Shariff and Norenzayan’s original findings. At the same time, various methodological problems have been identified in these recent replication attempts. These developments suggest the need for an independent large-scale direct replication of Study 2 of the original article, which we plan to provide.


​​​The limits of altruistic vaccination and the promise of stratified nudging:

A field experiment in a high-risk patient group

with Burcu Isler,Orestis Kopsacheilis Eamonn Ferguson 

[Under Review]

Influenza vaccine uptake remains low worldwide, inflicting substantial costs to public health and hospital operations. Messages promoting altruism have been shown to increase vaccination intentions, and it was recommended that health professionals communicate the altruistic aspects of vaccination. We test whether this altruistic vaccination hypothesis applies to actual vaccination behavior in a high-risk patient group. In a field experiment at a public hospital, we compare the effects of two messages for promoting vaccination that emphasized vaccine’s self or social benefits. We found no evidence for altruistic vaccination overall or among patients medically assessed to be at high risk. Exploratory analysis showed that emphasis on self-benefit was more influential among patients with high risk perceptions. Even if an emphasis on altruism could be effective among low-risk groups, our results suggest that an emphasis on self-benefit holds more promise for increasing vaccination in medical organizational settings where high-risk groups are prevalent.