11  Social Heuristics Hypothesis

written by Geffen Horowitz (original draft), and Katerina Michalaki (revision)

11.1 The Classic

Are humans – by nature – good? From Aristotle and Plato to Rousseau and Hobbes, the extent to which humans are instinctively cooperative or selfish has been largely debated. Aiming to answer this question is complicated, and has occupied philosophers and researchers of different disciplines alike. A social psychological take on this fundamental question aims to translate it into a hypothesis testable in an experimental setting.

The Social Heuristics Hypothesis (SSH) proposes that individuals develop and internalize prosocial cooperative intuitions through repeated exposure to everyday social environments where cooperation typically yields rewarding outcomes. In this context, heuristics refers to a set of mental shortcuts that support decision-making under uncertainty, but may lead to inaccurate and imperfect judgments (Kahneman 2011). These mental shortcuts are often applied automatically, reflect prior knowledge and reduce the cognitive load of information processing under conflicting and debatable conditions. In the social realm, it usually pays off to cooperate, and to help others, because one can expect them to cooperate, too. Therefore, we remember prosocial behavior and cooperation as beneficial strategies for behavior. These internalized strategies become embedded as prosocial heuristics that operate as fast and automatic responses, guiding behavior across diverse social situations: Acting prosocially and cooperatively becomes intuitive.

#definition Heuristic

Heuristics refer to simple processes that assist individuals to identify adequate, but imperfect, answers to complex questions (Kahneman 2011).

According to the SSH, humans extend prosocial heuristics beyond familiar contexts, applying them in novel or atypical situations where cooperation is not rewarded. In such contexts, the absence of reinforcing social cues may trigger controlled processing, a slower and effortful mode of reasoning marked by deliberative reflection and reduced emotional influence. Reflective processing may lead to suppression of intuitive prosocial decision-making, enforcing strategic and self-interested decision-making. The SSH frames social decision-making as a dual-process interplay between fast, effortless intuition and slower, deliberative reflection.

#definition Dual Process Theories

A set of theories that distinguish human thought into two sub-systems: a fast, intuitive system (System 1) and a slow, deliberate system (System 2). The former appears to be independent of cognitive control, whereas the latter is effortless and relies on working memory and cognitive capacity.

Across ten studies, Rand, Greene, and Nowak (2012) demonstrated that while reflective deliberation often unintentionally promotes selfish decision-making, prosocial cooperation tends to arise spontaneously as the intuitive human default. In 2012, Rand, Greene, and Nowak (2012) published a paper describing a series of studies that show a counter-intuitive conclusion – human intuitive behavior tends to be prosocial. Even if the loss from that kind of behavior is clear and known.

#definition Social Heuristic Heypothesis

A dual-process theoretical framework illustrating that social decision-making lies on internalized strategies that are considered advantageous in social encounters. People employ these intuitive responses in typical and atypical contexts. Under uncertain conditions, automatic responses may be overridden by effortful and evaluative processing that yields context-appropriate responses (Rand, Greene, and Nowak 2012).

#definition Prosocial Behavior

Prosocial behavior refers to the voluntary actions aimed at benefiting others, including sharing, helping, and confronting (Eisenberg and Fabes 1998).

This conclusion arises from a cognitive-behavioral mechanism which was found in a study using the Public Goods Game (PGG). The PGG is a widely used experimental paradigm for studying cooperation and social dilemmas. In the PPG, individuals make decisions about allocating resources between themselves and others. Typically, these decisions involve money that is paid to participants depending on their choices and the choices that others make. In the game, individuals decide whether to cooperate by contributing a portion of their resources to a public pool (think of this as a shared bank account), or to retain their resources for personal benefit. The total contributions to the public pool are shared equally among participants, regardless of individual contributions. This structure yields a conflict between collective and individual interest: although the group benefits most when all participants contribute, individual benefits may be higher by withholding contributions while still receiving a share of the group return. This experimental setup captures the tension between personal gains and joint benefits.

#definition Paradigm

The term paradigm refers to “the set of common beliefs and agreements shared between scientists about how problems should be understood and addressed” (Kuhn 1962). Paradigms reflect the assumptions associated with the state-of-affairs. In the experimental context, these assumptions directly shape the methodological strategies employed to address a research question and influence the interpretation of empirical findings.

#definition Social Dilemma

Social dilemmas refers to a set of scenaria in which individual and collective interests are mutually exclusive, yielding a conflict between selecting strategies that increase personal over collective benefits. Although selfish decisions are typically rewarded, personal gains are reduced if a substantial number of individuals aim for maximum gains (“APA Dictionary of Psychology” 2018).

#definition Public Goods Game

Public Goods Games (PGG) refer to multi-player experimental scenarios in which individuals are required to suppress selfish behavior and cooperate to attain a mutually beneficial outcome. In this design, individuals can choose to voluntarily contribute to a common pool that will be multiplied and equally distributed across all group members. Individuals who do not contribute may free-ride on the contribution of cooperators which imposes the risk of exploitation. Although avoiding contribution is commonly rewarded in PGG, if the number of defectors is large no collectively beneficial outcomes are achieved (Gómez-Gardeñes et al. 2011; Tomassini and Antonioni 2020).

#yourturn

Can you think of a situation where you might encounter a similar decision problem in the real world?

Public good games bring real-world situations in the lab, where the conflict between short-term incentives and long-term gains is strategized. Outside the laboratory, PGG reflects the strategic complexity of social, economic and policy-making dilemmas. For instance, in the context of sustainable energy and agriculture free-riding through underinvestment is not punished, but both cooperators and defectors will likely meet the environmental benefits. By translating these complicated situations to a simple experimental procedure, it becomes possible to study them in the lab or online. This also makes it possible to test the impact of experimental interventions on the procedure – as in the studies by Rand and colleagues.

In such a game, when one plays only a single round, it is more beneficial not to contribute to the “public pool” at all. Rand, Greene, and Nowak (2012) examined two competing hypotheses concerning the role of intuition and reflection in cooperative decision-making. According to the first hypothesis, self-interest represents the intuitive default, with prosocial behavior emerging exclusively through effortful reflection that overrides fundamental egocentric impulses. In contrast, the second hypothesis posits that prosocial behavior is supported by intuitive processes, whereas self-interested choices result from effortful reflective processing.

#definition Intuitive behavior

Behavior that occurs through automatic, prepotent and effortless cognitive operations. Commonly referred to as “System 1”, these mental operations are fast, associative and hard to control (Kahneman, 2002; Stanovich & West, 2000).

#definition Reflective behavior

Reflective behavior is supported by “System 2” and relies on effortful and slow mental operations that are deliberately controlled through reason (Kahneman, 2002).

Rand, Greene, and Nowak (2012) conducted a series of studies examining whether intuitive decision-making fosters cooperation. In the first study, participants who made faster, intuitive decisions contributed more to the public pool compared to those who made slower decisions. Study 2 included re-evaluation of data collected from former published social dilemma studies. Subsequent laboratory and online studies were conducted to investigate the causal relationship between intuition and prosocial behavior. Across 8 studies Rand and colleagues (2012) manipulated decision-making conditions to promote either reflective or intuitive processing. Intuition was evoked through time pressure that encouraged rapid responses. Reflection was induced by requiring participants to delay their decisions.

#definition Causal Relationship

A causal relationship refers to the situation when an event is the direct result of a preceding event. In the research context, causal relationships occur when the manipulation of an independent variable causes and explains the observed effects in a dependent variable that would otherwise not occur. Conversely, correlation is a statistical measure that describes the magnitude and direction of the relationship between two or more variables. In contrast to causal relationships, correlation does not imply that changes in the independent variable will automatically lead to and explain the observed effects in the dependent variable.

Participants in these studies were randomly allocated to one of two conditions. Participants assigned in the intuition condition were asked to form a decision within 10 seconds. Participants in the time-delay condition were asked to consider their decision carefully and to wait for at least 10 seconds before deciding.

#yourturn

When do you use the reflective or the intuitive system to make decisions?

Participants in these studies were randomly allocated to one of two conditions. Participants assigned in the intuition condition were asked to form a decision within 10 seconds. Participants in the time-delay condition were asked to consider their decision carefully and to wait for at least 10 seconds before deciding.

#yourturn

What are the potential benefits and costs of deliberate decision making? And of intuitive decision making?

In an online study one of the studies Rand and colleagues (2012) et al. used an additional priming manipulation. Participants in the intuition condition were asked to write a paragraph about a situation where intuition resulted in a beneficial decision or reflective reasoning led to a negative outcome. Conversely, participants in the reflection condition were instructed to write a paragraph about a situation in which an intuition-derived decision led them in the wrong direction or a reasoning-derived decision contributed to a favorable outcome.

Across all these studies, Rand and colleagues (2012) found the same effect: Participants in the intuitive group had contributed more to the public pool compared with the participants in the reflection group. In other words, intuitive decision making promoted prosocial behavior. Deliberate decisions were more selfish.

11.2 The Aftermath

Many researchers attempted to replicate findings of the studies conducted by Rand, Greene, and Nowak (2012), but not all of them found similar effects (Bouwmeester et al. 2017; Lohse 2016; Tinghög et al. 2013; Verkoeijen and Bouwmeester 2014).

In a registered replication report, Bouwmeester et al. (2017) also tested the causal effect of time pressure on prosocial cooperative behavior. They brought together 21 teams of researchers who conducted preregistered replication studies, aiming to show the findings of Study 7 by Rand, Greene, and Nowak (2012). To do this, they closely followed the procedure of the original study and made sure to note any deviations.

At the first glance, Bouwmeester et al. (2017) failed to replicate the findings. Including all participants who adhered to the study protocol in an intent-to-treat analysis showed no evidence that time pressure made participants more prosocial than time delay. In this analysis of the replication study, a difference in contributions of −0.37 percentage points between participants in the time pressure and the time-delay conditions was estimated. The original study had estimated a difference of 8.6 percentage points in contributions between the conditions.

However, the team noticed an important difference in how they approached the analyses and how the original research did: Rand, Greene, and Nowak (2012) excluded all participants who did not comply with the instructions (to decide quickly or to decide only after a certain delay). When the replicators did the same and analyzed the data only from compliant participants, results yielded statistically significant differences in contributions between the time-delay and time-pressure conditions. These results showed that among the participants who complied with the manipulation, intuitive decisions supported more prosocial behavior compared to deliberate decisions. Nevertheless, the effect was smaller than in the original publication. Rand, Greene, and Nowak (2012) reported a difference of 15.31 percentage points between the average contributions between the two conditions, the registered replication report estimated a difference of 10.37 percentage points. This deviation is not surprising and shows that the original study yielded inflated effects, whereas the replication study led to more conservative estimates. This effect is commonly referred to under the term “regression shrinkage” which may arise from sampling noise, leading to inflated estimates that diminish in subsequent replications where sample sizes are larger (Fiedler and Prager 2018). Evaluation of reliability estimates, manipulation checks, and potential sampling noise are critical for addressing the substantial impact of regressive shrinkage in replication studies.

11.3 Conclusion

The observed deviations highlight the importance of maintaining strict adherence to experimental procedures that are empirically-informed. Specifically, these findings highlight the potential issues that arise from the lack of evidence-based exclusion criteria which may unintentionally create systematic differences between experimental conditions. These practices make it difficult to replicate previous findings. In the original study, participants who responded too slowly in the intuition condition were omitted from analysis. This decision is particularly important in light of findings showing a negative correlation between response time and cooperation ; faster decisions being more strongly associated with prosocial behavior (Rand, Greene, and Nowak 2012). By excluding slow respondents, the researchers may unintentionally have introduced a systematic bias that artificially inflates cooperation levels in the time-pressure condition. Simultaneously, excluding non compliant performance scores may lead to several forms of bias that undermine random assignment procedures (Evans, Dillon, and Rand 2015; Krajbich et al. 2015).

Given these limitations, further replication studies to investigate the effects of time-pressure on prosocial behavior are required. Since alternative explanations cannot be rejected, including individual differences and personality traits, further investigation is required to map the causal effects of reflection and intuition on cooperative behavior.

Considering the methodological challenges in modifying the time-pressure condition to ensure that participants adhere to the time constraints, future studies could utilize alternative methodological approaches to evoke automatic, intuitive or effortful, deliberative processing. An interesting idea would be to design a replication study with different operationalization of the two conditions similarly to Study 7 by Rand, Greene, and Nowak (2012). For instance, priming participants with a situation in which intuitive and reasoning-derived decisions resulted in either positive or negative outcomes could lead to effective manipulation treatments with limited non-compliant exclusions.

The Social Heuristics Hypothesis (SHH) posits that people internalize cooperative strategies from everyday interactions because of the advantage that they entail. These strategies become intuitive defaults, guiding fast, automatic prosocial decisions not only in daily life, but sometimes in less conventional settings including the laboratory settings. According to this viewpoint, individuals may suppress these intuitive tendencies and act more strategically or selfishly, when they engage in slower, reflective reasoning. Although initial evidence (Rand, Greene, and Nowak 2012) supported this view, subsequent replications produced smaller or inconsistent effects, highlighting the role of methodological and contextual variation. Such variation may stem from differences in how experimental contexts shape the salience or strategic value of cooperation: when attention to others’ outcomes is more strongly cued or socially reinforced, intuitive prosociality under time pressure is more likely to emerge (Teoh and Hutcherson 2022). As the SHH field continues to develop, it stands to benefit greatly from the principles of open science and rigorous replication. Preregistered designs, transparent data sharing, and cumulative replication efforts can help clarify when and why intuitive prosociality emerges, strengthen the empirical foundation of the theory, and refine our understanding of how social context and cognitive processes jointly shape cooperative behavior.