Normative theories of judgment either focus on rationality (decontextualized preference maximization) or reasonableness (pragmatic balance of preferences and socially conscious norms). Despite centuries of work on these concepts, a critical question appears overlooked: How do people’s intuitions and behavior align with the concepts of rationality from game theory and reasonableness from legal scholarship? We show that laypeople view rationality as abstract and preference maximizing, simultaneously viewing reasonableness as sensitive to social context, as evidenced in spontaneous descriptions, social perceptions, and linguistic analyses of cultural products (news, soap operas, legal opinions, and Google books). Further, experiments among North Americans and Pakistani bankers, street merchants, and samples engaging in exchange (versus market) economy show that rationality and reasonableness lead people to different conclusions about what constitutes good judgment in Dictator Games, Commons Dilemma, and Prisoner’s Dilemma: Lay rationality is reductionist and instrumental, whereas reasonableness integrates preferences with particulars and moral concerns.

These theoretical claims remain untested and stand in contrast to a view that in everyday language these concepts appear equivalent. After all, the two terms derive from the same etymological root ( 18 ). However, if folk understanding of rationality versus reasonableness aligns with behaviors expected from a rational person in game theory and a reasonable person in legal scholarship ( 17 , 19 ), respectively, then framing decisions in terms of rationality versus reasonableness may prompt people either to maximize their preferences as advocated in neoclassical economics or to flexibly integrate others’ interests as advocated in ethics ( 20 – 22 ) and political theory ( 23 ). The chief goal of the present research was to test this possibility.

The distinction between rationality and reasonableness for people’s everyday decisions can be traced back to political and legal theories (see the Supplementary Materials), some claiming that people internalized the chief features of scholarly definitions: rationality as a formal and instrumental standard ( 13 ), the capacity to exercise judgment in defining one’s key preferences and selecting effective means to pursue those preferences ( 14 ); reasonableness as a context-dependent and pragmatic standard, balancing realist expectations of most common actions and normative concerns ( 15 ) in a respectful way ( 4 , 16 , 17 ).

If laypeople view rationality and reasonableness as distinct standards of judgment, then deviations of behavior from game theoretical models may not reflect judgment errors ( 8 , 10 , 11 ), but rather people’s use of a reasonable standard to guide their choices. To explore how people use rationality and reasonableness in their lives, here we use a telescopic approach. First, we examine folk concepts of rational and reasonable actors via content analyses of ascribed characteristics and attributions of personality and behaviors, showing that a rational agent is viewed as a preference maximizer, whereas a reasonable agent is viewed as a satisficer. Moving to implicit norms for reasonable and rational actors, we performed analyses of cultural products ( 12 ): news, soap operas, legal opinions, and corpora of English, Spanish, Portuguese, and Russian books. We show that linguistic use of “rational” is abstract and individual focused, whereas “reasonable” is context sensitive and socially focused. In subsequent 13 experiments, we demonstrate framing effects of rationality versus reasonableness on expectations and behavior in Commons Dilemma, Dictator Games, and Prisoner’s Dilemma, with expectations for reasonable/rational judgments converging and diverging depending on others’ cooperation- versus competition-signaling behaviors. Last, we replicate the evidence concerning dissociation of rational versus reasonable behavior in a socioeconomically diverse non-Western society.

What are the key features of a sound judgment? In game theory and dominant streams of economics, sound judgment is intimately linked with the notion of the rational person—a formal, preference-maximizing agent ( 1 – 3 ). In a disparate literature on political and legal theory, at least since the Roman times, sound judgment has been linked with the well-defined standard of a reasonable person—a pragmatic, socially conscious observer ( 4 – 7 ). Decades of research in behavioral economics have shown that people often fall short of the rational standard ( 8 – 10 ), raising the question: How do laypeople understand rationality and do they systematically differentiate it from reasonableness?

RESULTS

Studies 1 and 2: Personality, stereotypes, and behavioral attributes of rational versus reasonable persons In preregistered studies 1 and 2, we examined spontaneous descriptions of people who behave rationally and reasonably and examined attributions of personality characteristics (24), societal stereotypes (25), and maximizing and satisficing behaviors (26) to rational/reasonable actors. As Fig. 1 shows, rational and reasonable were among the most frequent descriptions of each other. The similarities in the descriptors of rational and reasonable actors concerned thoughtfulness, calmness, and intelligence. Consistent with our predictions, we also observed substantial differences. Descriptions of rational persons were more likely to concern abstract and decontextualizing characteristics such as logic, systematicity, analytical skills, and emotional suppression, whereas descriptions of reasonable persons were more likely to include socially conscious characteristics such as honesty, kindness, fairness, and interpersonal sensitivity (also see table S2). We cross-validated these results via hypothesis-blind content analyses, showing that stoic, logic-, and intelligence-oriented characteristics were significantly more likely to be attributed to rational persons (|Zs| > 2.84, P < 0.005), whereas morality- and interpersonally oriented characteristics were significantly more likely to be attributed to reasonable persons (|Zs| > 4.33, P < 0.001). There were no significant differences in attributions of levelheadedness and objective/professional characteristics. Fig. 1 Spontaneous ascriptions of reasonable vs. rational persons. (A) Common themes in descriptions of rational and reasonable persons. (B) Themes differentiating reasonable (in blue on top) from rational (in brown on the bottom); size of the word is mapped to its maximum deviation across reasonable versus rational text corpora. Examination of questionnaire-based personality and stereotype-related characteristics yields similar results. As Fig. 2 indicates, participants were significantly more likely to associate the term “reasonable” rather than “rational” with adjectives representing socially oriented characteristics (honesty/humility, agreeableness, emotionality, and extraversion) (2.52 < ts < 3.68, 0.012 < P < 0.001). Societal stereotypes of rational persons concerned relatively greater agency (t = 3.89, P < 0.001), whereas stereotypes of reasonable persons concerned greater communion (t = 6.70, P < 0.0001) and lower selfishness (t = 3.77, P < 0.001). Moreover, rational persons were viewed as maximizers—pursuing the best option and searching through all alternatives [3.56 < t(df = 240) < 6.28, Ps < 0.001], whereas reasonable persons were viewed as satisficers, accepting the best acceptable option [t(df = 240) = 2.66, Ps = 0.008]. Fig. 2 Personality, stereotypes, and behavioral attributes of reasonable vs. rational persons. (A) Difference in attribution of personality characteristics to reasonable versus rational persons. (B) Difference in cardinal stereotype dimensions of agency and communion ascribed to reasonable versus rational persons, along with ascription of selfishness. (C) Expectation of maximizing (alternative search; goal of choosing the best) and satisficing behavior to reasonable versus rational agents. (A) to (C) show violin plots with density distribution of difference scores, 25% median, 75% quantiles, boxplots, estimated means, and bootstrapped 95% confidence intervals. Scores above zero indicate greater attribution to reasonable persons. As supplementary analyses show, people’s views of rational and reasonable persons were comparatively consistent, whereby the views of a reasonable (versus rational) person were uniquely aligned with attributions of agency, communion, and selfishness to an ideal person. Moreover, characteristics of rational and reasonable persons explained independent variance in attributions of competence to an ideal person. These results both oppose the idea that rationality represents a sole standard of judgment or that reasonableness is a vague, low-relevance concept for judgmental competence (also see consistency of distributions of expected behavior by reasonable versus rational actors in Fig. 3). Fig. 3 Rationality is associated with individual-focused nouns and rational expectations in a Dictator Game (DG), reflecting preference maximization, whereas reasonableness is associated with socially conscious nouns and reasonable DG expectations, reflecting greater fairness. (A) Human-coded percentage of individual/abstract and social/contextual themes in sentences involving “rational” and “reasonable” in text corpora. (B) Dictator Game sharing with the other player by reasonable and rational people (studies 5a and 5c), personal sharing (studies 5b and 5c), and an average student (study 5c). Figure represents density distributions, boxplots, and estimated means with 95% confidence interval at α = .05 obtained via bootstrapping with 1000 samples.

Studies 3 and 4: Computerized and human-coded content analyses of news on the web, American soap operas, SCOTUS opinions, Google books, and national corpora In study 3, we examined over 5 billion words of data from web-based English language news sources from January 2010 to September 2017—the largest corpus of everyday English language to date. Specifically, we explored the top 100 nouns most frequently following “reasonable” and “rational,” quantifying unique associations and classifying words as abstract/person focused and context sensitive (i.e., variation across either intertemporal or social interpersonal contexts) via human coders. We reasoned that term-specific associations (e.g., idioms) would carry the psychological meaning of the respective constructs. Human-guided content analyses revealed that 33% of nouns following “rational” were classified as abstract/person focused, compared with 6% of nouns following “reasonable” [χ2(df = 1, N = 200) = 23.22, P < 0.0001, Cramer’s V = 0.341]. Conversely, 40% of nouns following “reasonable” were classified as reflecting contextual contingencies, but only 4% of nouns following “rational” [χ2(df = 1, N = 200) = 37.76, P < 0.001, Cramer’s V = 0.435; see Fig. 3]. We cross-validated our content analyses on soap operas and Supreme Court of the United States (SCOTUS) opinions. In soap operas, compared with 36% of nouns following “rational” classified as abstract/person focused, only 23% of nouns following “reasonable” were classified as abstract/person focused [χ2(df = 1, N = 140) = 2.79, P = 0.095, Cramer’s V = 0.141]. Conversely, 28% of nouns following “reasonable” were classified as reflecting contextual contingencies, whereas only 10% of nouns following “rational” were classified into this category [χ2(df = 1, N = 140) = 7.76, P = 0.005, Cramer’s V = 0.235]. In SCOTUS opinions, compared with 89% of nouns following “rational” classified as abstract/person focused, only 38% of nouns following “reasonable” were classified as abstract/person focused [χ2(df = 1, N = 200) = 56.11, P < 0.001, Cramer’s V = 0.530]. Conversely, 72% of nouns following “reasonable” were classified as reflecting contextual contingencies, whereas only 43% of nouns following “rational” were classified into this category [χ2(df = 1, N = 200) = 17.21, P < 0.001, Cramer’s V = 0.293]. These observations indicate that the notion of reasonableness in cultural products is more likely to take contextual particulars (intertemporal uncertainty and interpersonal considerations) into account, whereas the notion of rationality appears to chiefly focus on the abstract, individual attributes and preferences. In study 3b, we further bolstered this inference by examining the relative frequencies of definite (“the”) and indefinite (“a”) articles preceding utterances reflecting “reasonable” and “rational” judgment (utterances finishing with “action”/“decision”/“thing to do”). In this context, indefinite articles indicate a general recommendation because they imply that more than one approach could be appropriate (e.g., “a reasonable action”), whereas the definite article indicates the application of a rule because it implies that only one approach is appropriate (e.g., “the rational thing to do”). We examined both the news corpus and the American Google Books—the largest corpus of English books available to date (27). In the news, statements reflecting rational judgments were 1.41 times more likely to be preceded by the definite article than statements reflecting reasonable judgments. Conversely, statements reflecting reasonable judgments were 3.84 times more likely to be preceded by the indefinite article than statements reflecting rational judgments. Results were similar for Google books, with definite articles 1.40 times more likely to precede rational judgments and indefinite articles 2.10 times more likely to precede reasonable judgments. Does the distinction between reasonableness and rationality exist in other languages beyond English? In study 4, we addressed this question by extending human-coded content analyses of the top 100 associations in the Spanish and Portuguese corpora of Google Books, as well as a random subset of 100 sentences including reasonable/rational in the Russian National Corpus (see Supplementary Materials for methods of identifying key terms and their translation). Similar to English, 45 to 70% of nouns following “rational” were classified as individual focused, compared with 15 to 18% of nouns following “reasonable”: Spanish, χ2(df = 1, N = 200) = 30.73, P < 0.0001, Cramer’s V = 0.392; Portuguese, χ2(df = 1, N = 200) = 19.84, P < 0.0001, Cramer’s V = 0.315; Russian, χ2(df = 1, N = 200) = 54.87, P < 0.0001, Cramer’s V = 0.524. Conversely, 43 to 56% of nouns following “reasonable” were classified as reflecting contextual contingencies, whereas only 5 to 14% of nouns following “rational” were classified into this category: Spanish, χ2(df = 1, N = 200) = 27.02, P < 0.0001, Cramer’s V = 0.368; Portuguese, χ2(df = 1, N = 200) = 43.14, P < 0.0001, Cramer’s V = 0.464; Russian, χ2(df = 1, N = 200) = 43.14, P < 0.0001, Cramer’s V = 0.464. Overall, analyses of written media in English-, Spanish-, Portuguese-, and Russian-speaking countries show qualitatively distinct norms of reasonableness and rationality, such that reasonableness includes interpersonal consideration and focuses on contextual particulars. Conversely, the standard of rationality appears to reflect decontextualized judgments aligned with individual attributes and instrumental preferences.

Study 5: Expectations for rational and reasonable agents in a Dictator Game In subsequent experiments, we examined how people differentiate rationality and reasonableness when evaluating choices in the context of a Dictator Game (9)—a behavioral economic game where player A can choose what fraction of a resource ($10) to share with anonymous player B, who must accept the offer. If the cultural associations between rationality and individual preference maximization and reasonableness and socially conscious considerations are internalized at the individual level, then we should find that people expect rational choices to be more preference maximizing and reasonable choices to be more socially conscious. In three experiments, we varied design (within versus between subject), examined different populations (see table S1), and tested several boundary conditions (see Supplementary Materials for more details). In studies 5a and 5b, Amazon Mechanical Turk (MTurk) workers reported expected contributions by reasonable and rational persons in player A’s role. Study 5c replicated effects on university students and explored whether predicted actions for reasonable or rational agents are closer to the perceived typical person in their community and their personal choice as player A. As Fig. 3 shows, reasonable people were expected to share on average 7 to 20% more than rational people. Reasonable people were expected to share more than rational people: study 5a, t(281) = 5.42, η p 2 = 0.095; study 5b, t(960.89) = 5.23, η p 2 = 0.027; study 5c, t(206) = 8.96, η p 2 = 0.280 (all Ps < 0.001); a perceived average student: study 5c, t(206) = 9.07, η p 2 = 0.290 (P < 0.001); or oneself: study 5b, t(491) = 3.83, η p 2 = 0.029; study 2c, t(206) = 4.95, η p 2 = 0.290 (all Ps < 0.001). Conversely, average personal sharing was significantly higher than those expected for a rational person [study 5b: t(493) = 2.85, P = 0.005, η p 2 = 0.016; study 5c: t(206) = 5.49, P < 0.001, η p 2 = 0.128] or the perceived average student [study 5c: t(206) = 5.02, P < 0.001, η p 2 = 0.109]. The latter observation dovetails with earlier work on cynical, asymmetric expectations of selfishness by others versus oneself (28, 29). The observed dissociation was robust to changing scale direction (unreasonable versus irrational) and question form [asking what reasonable/rational people would give versus asking what would be the reasonable/rational amount; (12)]. Moreover, self-perceptions of reasonableness and rationality predicted anticipated decisions: Participants who viewed themselves as reasonable shared significantly more (β Exp5b = 0.10, t = 2.51, P = 0.01; β Exp5c = 0.33, t = 4.96, P < 0.001), whereas participants who viewed themselves as rational shared less (β Exp5b = −0.06, t = 1.49, P = 0.14; β Exp5c = −0.24, t = 3.62, P < 0.001).

Studies 6 and 7: Rational and reasonable personal choice Two subsequent experiments used between-subject designs and revealed that the distinction between reasonable versus rational agents extends to framing of personal choices (16). Participants intended to donate 5% more money in a Dictator Game if they were seeking to be reasonable versus rational (see fig. S2): study 6a, t(353.76) = 2.65, P = 0.009, η p 2 = 0.016; study 6b, t(493.56) = 2.01, P = 0.045, η p 2 = 0.008. Study 6b simultaneously tested the impression of selfishness, agency, and communion for rational versus reasonable people. Reasonable people were perceived as less selfish than rational people [t(511) = 3.87, P < 0.001, η p 2 = 0.028], and this difference in selfishness mediated the difference in predicted sharing by reasonable versus rational people (Z = 3.19; 95% CI bootstrapped , 0.094 to 344). Do these effects extend to personal choice on an independent task? In the preregistered study 7 (osf.io/sy24t), participants recalled reasonable or rational actions from their lives and subsequently took part in a standard Dictator Game. Recall of a reasonable action resulted in 3.18% higher offers in the Dictator Game (M = $4.28, SD = 1.91) than recall of a rational action (M = $3.96, SD = 2.01) [Wald (df = 1) = 7.79, P = 0.005] (see fig. S3). This effect holds when controlling for socioeconomic factors (age, gender, and income) [Wald (df = 1) = 8.21, P = 0.004] and with nonparametric analysis of results (U = 167,998, P = 0.006). Whereas 14.15% of participants in the rational condition donated none of the endowment to the other person, only 9.56% of participants in the reasonable condition suggested donated nothing [N = 1116, χ2(df = 1) = 5.67, P = 0.017, Cramer’s V = 0.07]. Conversely, 71.01% of participants in the reasonable condition donated at least half of the endowment to the other person, whereas only 65.47% in the rational condition did so [N = 1116, χ2(df = 1) = 5.56, P = 0.018, Cramer’s V = 0.07].

Studies 8 and 9: Use of reasonable versus rational standards and generalizability across dilemmas and interpersonal transactions Study 8 extended the distinction between rational and reasonable standards to expectations in two other classic economic games where a person’s preference conflicts with others’ interests—Commons Dilemma and Prisoner’s Dilemma (30). Participants expected rational people to withdraw 12% more from the common pool as compared with reasonable people in the Commons Dilemma [t(305) = 5.27, P < 0.001, η p 2 = 0.083]. In the Prisoner’s Dilemma, participants expected rational people to pick defecting and cooperative options to a similar extent (defect = 197/cooperate = 190) but expected reasonable people to overwhelmingly select a cooperative option (defect = 84/cooperate = 303) [N = 387, χ2(df = 1) = 7.04, P = 0.008, Cramer’s V = 0.14]. Given the intermediate position of personal choices between rational and reasonable people (Fig. 3), we examined whether participants use the reasonable versus rational choice distinction in economic and interpersonal transactions to their benefit. Specifically, if laypeople internalize both preference-maximizing features of rationality and socially conscious features of reasonableness standards, it is possible that they systematically favor a rational agent in self-focused situations and a reasonable agent in other-focused situations. Study 8 addressed this question in the context of economic games (Dictator Game, Commons Dilemma, and Prisoner’s Dilemma), whereas study 9 extended it to negotiations, legal disputes, and managerial decision-making. For each situation, participants indicated whether they would prefer a reasonable or a rational agent to act on their behalf and on behalf of another party (in a randomized order). In both studies, participants overall favored a rational agent more than a reasonable agent to act on their behalf: study 8, Wald χ2(df = 1) = 39.40, P < 0.001; study 9, Wald χ2(df = 1) = 7.92, P = 0.005 (see Fig. 4). Conversely, participants favored a reasonable over a rational agent for the other parties involved in a dilemma: study 8, Wald χ2(df = 1) = 21.63, P < 0.001; study 9, Wald χ2(df = 1) = 85.38, P < 0.001. See the Supplementary Materials for scenario-specific analyses and results. Fig. 4 Preference for rational and reasonable agents for self and other across a range of economic and social situations, as well as attributions of rationality, reasonableness, and kindness to cooperating versus defecting behavior in a Prisoner’s Dilemma. (A) Rational agent is preferred to act on one’s behalf, and reasonable agent is preferred to act on behalf of another party in studies 8 and 9. (B) Attribution of reasonableness is more pragmatic compared with rationality and kindness, as demonstrated by switching in asymmetric multitrial Prisoner’s Dilemma. CDC (prosocial consistency): player A cooperates on round 1, player B defects, and player A continues cooperating on round 2. CDD (punishment): Player A cooperates on round 1, player B defects, and player A defects on round 2. DCC (prosocial switching): player A defects on round 1, player B cooperates, and player A cooperates on round 2. DCD (antisocial consistency): Player A defects on round 1, player B cooperates, and player A continues defecting on round 2. Error bars represent confidence intervals (CIs) at α = .05 obtained via bootstrapping with 1000 samples.

Studies 10 and 11: What actions are rational, reasonable, and kind? We examined how expectations for reasonable and rational judgments converge and diverge depending on the situation (others’ cooperative versus competitive-signaling behaviors) as a way to further probe whether people view rationality and reasonableness as distinct standards rather than opposite sides of the same evaluative dimension of prosociality. In study 10, participants evaluated reasonableness and rationality of a player in single- and multiround Prisoner’s Dilemmas (see top panel of fig. S4 for types of transactions). In study 11, we rerun the two-round games, simultaneously comparing evaluations of reasonableness to kindness. In single-round games, cooperating players were viewed as more reasonable (versus rational) and defecting players more rational (versus reasonable) [F(1,590) = 57.71, P < 0.001, η p 2 = 0.089]. In two-round games, when both players behave similarly on round 1 (symmetric game), cooperating on round 2 is viewed as more reasonable and defecting on round 2 is viewed as more rational: study 10, F(1,590) = 45.44, P < 0.001, η p 2 = 0.072; study 11, F(1,733) = 99.01, P < 0.001, η p 2 = 0.119. Conversely, under asymmetric conditions of unilateral cooperation by player A on round 1, player A was viewed as equally more rational and reasonable when choosing to defect rather than cooperate on round 2: study 10, F(1,590) = 35.18, P < 0.001, η p 2 = 0.056; study 11, F(1,739) = 35.27, P < 0.001, η p 2 = 0.046. Notably, under asymmetric conditions of unilateral defection by player A on round 1, player A was viewed as equally rational when choosing to cooperate or defect on round 2 but was only viewed as reasonable when choosing to cooperate but not defect again on round 2: study 7, F(1,589) = 67.84, P < 0.001, η p 2 = 0.103; study 11, F(1,739) = 82.69, P < 0.001, η p 2 = 0.101. The latter observations suggest that depending on the situation, participants considered a given choice as high in rationality and low in reasonableness, low in rationality and high in reasonableness, or as high in both rationality and reasonableness. These results support the idea that people view rationality and reasonableness as distinct standards of judgmental competence rather than merely opposite sides of the same evaluative (prosociality) dimension. Attributions of reasonableness significantly differed from attributions of kindness: symmetric game, F(1,733) = 119.86, P < 0.001, η p 2 = 0.141; asymmetric game, F(1,739) = 44.17, P < 0.001, η p 2 = 0.056. As Fig. 4 indicates, cooperative actions were viewed as kinder rather than more reasonable, whereas reciprocal cooperation after initial defecting and punishment of nonreciprocation after initial cooperation were viewed as reasonable but not kind. Overall, studies 11 and 12 demonstrate that preferences for rational or reasonable agents are conditional on situational goal demands: When choosing an agent that can maximize one’s preferences, people select a rational person, but when choosing an agent that is socially conscious and considerate of other party’s needs, people select a reasonable person.