Doi:10.1016/j.evolhumbehav.2004.12.006

Evolution and Human Behavior 26 (2005) 375 – 387 Altruistic punishing and helping differ in sensitivity to relatedness, friendship, and future interactions Rick O’Gormana, David Sloan Wilsona,b,*, Ralph R. Millerc aDepartment of Biological Sciences, Binghamton University, Binghamton, NY 13902-6000, USA bDepartment of Anthropology, Binghamton University, Binghamton, NY 13902- 6000, USA cDepartment of Psychology, Binghamton University, Binghamton, NY 13902- 6000, USA Initial receipt 26 January 2004; final revision received 17 December 2004 Altruism is behaviorally defined as an act that benefits others at the expense of the actor. Altruism is usually associated with helping others in need, but it can also take place in the context of punishment.
People who help to maintain cooperation by punishing cheaters are benefiting others at their ownexpense as surely as if they performed acts of overt helping. The proximate psychological mechanismsthat motivate altruistic helping and altruistic punishment are almost certainly different from each other(e.g., empathy vs. moralistic anger). We present two studies suggesting that the impulse to altruisticallyhelp and altruistically punish differ in their sensitivity to information regarding genetic relatedness andprobability of future interactions. This interesting empirical result is relevant to the interpretation ofaltruistic punishment as an evolved adaptation versus a byproduct of modern environments, and to theevolution of psychological traits associated with morality.
D 2005 Published by Elsevier Inc.
Keywords: Altruism; Altruistic punishment; Altruistic helping; Kin selection; Reciprocity; Morality * Corresponding author. Department of Biological Sciences, Binghamton University, Binghamton, NY 13902 - 6000, USA. Tel.: +1 607 777 4393; fax: +1 607 777 6521.
E-mail address: [email protected] (D.S. Wilson).
1090-5138/05/$ – see front matter D 2005 Published by Elsevier Inc.
doi:10.1016/j.evolhumbehav.2004.12.006 R. O’Gorman et al. / Evolution and Human Behavior 26 (2005) 375–387 Altruism is defined by evolutionary biologists as an act that increases the fitness of others while decreasing the fitness of the actor. This definition makes no reference to thepsychological mechanisms that motivate the act, which might or might not count asaltruistic as psychologists and philosophers use the term. Fitness effects andpsychological mechanisms can be understood and related to each other in terms of theevolutionary distinction between ultimate and proximate causation, as reviewed by and Wilson (1998).
Altruism has traditionally been studied in the context of helping, but punishment can also qualify as altruistic in terms of its fitness effects. Consider the simultaneous evolution oftwo traits: (1) an altruistic act such as providing a public good versus free-riding, and(2) punishing free riders versus failing to punish. Nonpunishers benefit from the policingefforts of the punishers in just the same way that free riders benefit from the public goodprovided by the altruists. Theoretical models show that altruistic punishment can favor theevolution of other altruistic acts that would not evolve in the absence of punishment Gintis, Bowles, & Richerson, 2003; Boyd & Richerson, 1992; Gintis, 2000; Henrich & Boyd,2001). Nevertheless, altruism supported by punishment does not necessarily evolve tofixation. Instead, a behavioral polymorphism often results, which includes public goodproviders, free riders, punishers, and nonpunishers.
Strong experimental evidence exists for this behavioral mix in humans, thanks largely to the efforts of economists Ostrom, Gardner, & Walker, 1994). In games where a public good can be provided at privateexpense, individuals differ in their tendency to free ride. Once the more generous members ofthe group realize that they are being exploited by free riders, they tend to withhold theiraltruism, resulting in the complete absence of public good provision. When the opportunity topunish free riders at private expense is added, some individuals elect to punish, in addition toproviding the public good. A sufficient number of punishers make free-riding disadvanta-geous, and public good provision rises to near maximum levels. Punishment can be regardedas self-interested, despite its private cost, if the punisher benefits from increased public goodprovision over the long term. However, numerous experiments have been performed in whichthe return benefits of punishment are rigorously excluded ).
These experiments show that some individuals punish only when it is in their perceived self-interest, but a sizeable fraction continues to punish in the complete absence of return benefits.
These experiments unequivocally demonstrate the existence of altruistic punishment inhumans at the behavioral level. The pronounced individual differences are also in accord withthe aforementioned theoretical models.
While the existence of altruistic punishment in humans is well established, its interpretation has become the subject of a vigorous debate. One possibility is that altruisticpunishment is an adaptation that evolved because bgroups with a high fraction of altruisticpunishers would have sustained cooperation more successfully than groups with fewerpunishers, and so would have prevailed over them Q , p. 128).
R. O’Gorman et al. / Evolution and Human Behavior 26 (2005) 375–387 Another possibility is that altruistic punishment is maladaptive in a modern context andonly makes sense in relation to the human ancestral environment. According to thismismatch hypothesis, people lack the cognitive adaptations for behaving appropriately inthe context of the experiments because social interactions invariably took place amonggenetic relatives or nonrelatives with a high likelihood of future interactions (Stopka, & Knights, 2003).
In this paper, we use fictional scenarios to explore the effects of information regarding genetic relatedness, friendship, and potential for future interactions in situations that invokealtruistic punishment and altruistic helping. We conducted two experiments, using fictionalscenarios that were similar to the aforementioned games involving actual interactions. Thefirst experiment was designed to test the effects of information regarding geneticrelatedness, friendship, and potential for future interactions on the desire to punish normviolations. The second experiment simplified and changed some details of the transgressionscenario and added an altruistic helping scenario. The advantage of this methodology isthat the elements of the scenarios can be systematically varied and presented to largenumbers of people in a way that would be difficult or impossible to stage with actualinteractions. Responses to fictional scenarios provide important insights into psychologicalmechanisms, even when they do not correspond directly to responses to actual interactions.
In our case, we demonstrate a remarkable difference between altruistic helping and altruisticpunishment in their sensitivity to information regarding genetic relatedness, friendship, andpotential for future interactions. This difference is relevant to the debate over altruisticpunishment and more generally to the evolution of psychological mechanisms associatedwith morality.
Four hundred seventy undergraduates (190 males, 279 females; 1 not reported; ages between 16 and 35 years, with a mean of 18.8) from an introductory Psychology courseat SUNY-Binghamton completed the present study as part of a mass testing session forcourse credit.
Participants were presented with a questionnaire that asked them to imagine themselves as members of an investment club who pool individual contributions of US$1000 each to playthe stock market. Information regarding friendship and genetic relatedness was manipulatedby describing the members as cousins, friends, or strangers prior to the formation of the club.
The probability of future interaction was manipulated by stating that everyone in the clubremained in the same town and were likely to interact again, that the cheater had moved toanother town and was unlikely to interact with any other member of the club, or that thesubject had moved to another town and was unlikely to interact with the cheater, whonevertheless was likely to interact with other members of the club. These conditions werecrossed in a 3Â3 between-group factorial design, yielding nine treatments.
R. O’Gorman et al. / Evolution and Human Behavior 26 (2005) 375–387 Participants are told that the investments triple in value, but one member cheats and takes US$2160 more than he deserves (see Appendix A for one version of the scenario). Thequestionnaire then directs participants to respond to the following questions: (1) How angry would you feel toward this person? Please answer on a scale from 1 (not at (2) How much would you like to punish this person? Please answer on a scale from 1 (no interest in punishing) to 9 (extremely interested in punishing)_____ (3) Although punishment can take many forms, if you think of it as a dollar amount, how much do you think this person should pay for what he or she did? US$______ (4) Punishing this person can take many forms, but if you think of it as a dollar amount, what is the most you would be willing to pay to punish this person? US$______ Considering all treatments together, participants responded to the scenario with a high average degree of anger (M = 7.4 on a nine- point scale, S.D.= 1.7) and desire to punish thetransgressor (M =6.1, S.D.=2.3). On average, they felt that the transgressor should pay backapproximately what he stole (US$2089.4, S.D.=2576.8), and they were prepared to pay amean of US$421.3 (S.D. =2140.1) to punish the transgressor. However, there were nostatistically significant differences among the treatments ( p N.2). The variables of geneticrelatedness, friendship, and potential for future interactions appeared to be psychologicallyirrelevant. There was also no main effect or interaction effects for sex, although it approachedsignificance for a main effect on desire to punish the transgressor ( p =.083; MMales=6.4,S.D.Males=2.2; MFemales=5.9, S.D.Females=2.4).
Another important result concerns the distribution of scores ), in addition to their mean values. The self - report of anger and desire to punish were so strong that thedistributions were truncated at the high end. In fact, the most common response for anger wasthe maximum value of nine. The distribution for the amount that the transgressor should payincludes a large spike corresponding to the amount that he stole, with other participantsindicating that he should pay more (retribution) or paradoxically less than he stole. Thedistribution for the amount that the participant would be willing to pay to punish thetransgressor shows that a large fraction of participants are willing to pay nothing or very little,while others are willing to pay a great deal. Taken together, these distributions suggest that,while most participants are very angry and would like to see the transgressor punished, onlysome are willing to altruistically punish.
Four hundred six undergraduates (159 males, 203 females; 44 not reported; ages between 17 and 33 years, with a mean of 18.9) from an introductory Psychology course R. O’Gorman et al. / Evolution and Human Behavior 26 (2005) 375–387 Fig. 1. Histograms of participants’ responses to the fictional scenarios in Experiment 1 [n is 463, 463, 417 and 431for (A), (B), (C), and (D), respectively]. Panel (A) shows the distribution of responses for reported levels of anger,showing that a majority of participants reported a high level of anger. Panel (B) shows that a substantial number ofparticipants also had a high desire to punish the transgressor. Panel (C) shows the amount of money thatparticipants thought the cheater should repay, with intervals of US$500 (the x axis labels show the upper limit ofthe corresponding interval). Panel (D) shows the amount of money that participants reported being willing to payto punish the transgressor, with intervals of US$2000 (the x axis labels show the upper limit of the correspondinginterval). The data show a dissociation between participants’ reported emotions and their willingness to punish.
at SUNY-Binghamton completed the present study as part of a mass testing session forcourse credit.
The materials and procedure were similar to those for Experiment 1. A second punishment scenario was added, in which a fellow group member proposes going to the sociallysanctioned mechanism of small claims court to seek redress, in addition to punishing thetransgressor in an unspecified fashion, as per Experiment 1. This version was added todetermine whether the results from our first experiment were due to a lack of a socially R. O’Gorman et al. / Evolution and Human Behavior 26 (2005) 375–387 acceptable (normative) means to punish the cheater. We also added an altruistic helpingscenario, in which one investing member had anticipated a profit to pay for emergencymedical bills and the participants were asked how much they would be willing to contributetoward helping.
Information regarding friendship and genetic relatedness was manipulated as in the first experiment, but the bfriendsQ treatment was dropped to limit the total number of treatments toaccommodate the socially sanctioned punishment scenario and the altruistic helping scenariowhile maintaining adequate sample sizes. The probability of future interaction was alsomanipulated as in the first experiment, with the treatment in which the participant had movedto another town dropped, again to limit the number of treatments, thus producing a 3Â2Â2between-group factorial design, yielding 12 treatments.
Participants were presented with a questionnaire that asked them to imagine themselves as members of an investment club who pool individual contributions of US$1000 each to playthe stock market. In the transgression scenario, the investments merely break even rather thanmaking a profit, except for the amount stolen by the transgressor, US$200. In the helpingscenario, the investments break even.
In the transgression scenario, participants were presented with the same questions as used in Experiment 1. Participants in the helping scenario were presented with the followingquestions: (1) How sorry would you feel toward this person? Please answer on a scale from 1 (not at (2) How much would you like to help this person? Please answer on a scale from 1 (no interest in helping) to 9 (extremely interested in helping)_____ (3) What is the most you would be willing to give to help this person? US$______(4) Some of the other group members want to help the person, but others seem unwilling to help if it costs them anything. How angry would you feel toward those who do notwant to help? Please answer on a scale from 1 (not at all angry) to 9 (extremelyangry)_____ The results of the second experiment confirmed the results of the first experiment in all essential details: Participants in the punishment treatments indicated strong anger at thetransgression (M = 6.4, S.D.=2.2) and a moderate to high desire to punish (M =5.4,S.D. =2.4) but were insensitive to information regarding genetic relatedness or potential forfuture interactions ( p N.16 for both main effects). Most wanted the transgressor to pay backwhat had been stolen (52.1%), and many were unwilling to pay to punish the transgressor(48.1%), despite their anger (see ). Providing a socially sanctioned mechanism forpunishment (small claims court) significantly decreased the average level of anger [M =5.9,S.D. = 2.2 for the treatments with small claims court option vs. M = 6.7, S.D. = 2.2;F(1,247) =8.58, p =.004] but did not increase the desire of participants to punish ( p=.26), R. O’Gorman et al. / Evolution and Human Behavior 26 (2005) 375–387 Fig. 2. Histograms of participants’ responses to the fictional scenarios in Experiment 2 [n is 249, 249, 240, and233 for (A), (B), (C), and (D), respectively]. Panel (A) shows the distribution of responses for reported levels ofanger, showing that a majority of participants reported a high level of anger. Panel (B) shows that a substantialnumber of participants also had a high desire to punish the transgressor. Panel (C) shows the amount of money thatparticipants thought the cheater should repay, with intervals of US$250 (the x axis labels show the upper limit ofthe corresponding interval). Panel (D) shows the amount of money that participants reported being willing to payto punish the transgressor, with intervals of US$250 (the x axis labels show the upper limit of the correspondinginterval). The data support the findings in Experiment 1. The less skewed data for Panel (A) contrast with thedistribution for Experiment 1 [Panel (A)], which is due to the manipulation of the presence or absence of anormative option to punish the transgressor by going to small claims court.
the amount they thought the transgressor should pay ( p =.83), or the amount that they werewilling to pay to punish ( p = .99).
There was a main effect for sex on desire to punish the transgressor [ F(2,238) =5.74, p =.004; MMales=6.0, S.D.Males=2.4, MFemales=5.0, S.D.Females=2.4] and near-significanteffect on level of anger [ F(2,238) =2.97, p =.05; MMales=6.6, S.D.Males=2.2, MFemales=6.2, R. O’Gorman et al. / Evolution and Human Behavior 26 (2005) 375–387 S.D.Females=2.2]. This suggests that females are emotionally more moderate in their responsesto the transgression, but this did not produce a sex effect for the amount that participantsthought the transgressor should pay ( p = .92) nor the amount that they were willing to payto punish ( p =.78). Furthermore, the stronger sex effect (on desire to punish the transgressor)did not produce notably different distributions for males and females for responses tothat question.
In contrast to the punishment scenario, participants were highly sensitive to information regarding genetic relatedness and potential for future interactions in the helping scenario.
Participants showed an overall moderately positive level of emotional sympathy for theindividual needing help (M =6.7, S.D. =2.2), a moderate willingness to help (M =6.6,S.D. =2.2), and a mean offer of financial assistance of US$553.1 (S.D.= 886.0). presents a summary of participants’ responses for each of the three dependent measures byperceived relatedness and potential for future interactions.
An analysis of variance showed that participants had greater sympathy for relatives versus strangers [ F(1,125)=4.51, p =.036] and for protagonists with an expected future interactionversus no future interactions [ F(1,125)= 8.8, p =.004]. For willingness to help, participantsmade similar distinctions between relatives and strangers [ F(1,125) =12.87, p b.0005] andbetween future and no - future situations [ F(1,125) =12.37, p =.001]. There was also aninteraction effect between those two variables [ F(1,125) =9.37, p =.003], with the stranger/no - future interactions treatment significantly differing in post hoc analysis from the otherthree treatments. Finally, participants in the altruistic helping treatment made significantdistinctions depending upon relatedness [ F(1,117)= 11.61, p = .001] for the amount that theywere willing to provide as assistance (participants were willing to provide a mean ofUS$831.50 to a cousin but only US$305.10 to a stranger), but not depending upon thelikelihood of future interactions [ F(1,117)= 0.18, p =.67]. There was a near- significant effectfor sex on level of sympathy [ F(2,118) = 3.0, p = .054; MMales = 6.4, S.D.Males = 2.1,MFemales=7.2, S.D.Females=2.0]. This suggests that females report feeling more sorry forthe protagonist, but this did not produce a sex effect for how much participants thought theyshould help ( p =.19) or how much they would contribute to help ( p =.96).
Table 1Mean values (S.D., n for cell) for responses to questions regarding the helping scenario The questions on sympathy for the protagonist and willingness to help the protagonist had a response scale of1 to 9. The question asking how much help would participants provide to the protagonist, quantified as dollars,was open; that is, participants could suggest any amount that they wished. Note that while all participants werepresented with the three questions, the cells present data for independent subjects, not repeated measures.
R. O’Gorman et al. / Evolution and Human Behavior 26 (2005) 375–387 Our fictional scenarios were designed to resemble a large body of research involving actual interactions and gave comparable results. In particular, some but not all participants indicateda willingness to punish at their own expense despite the absence of return benefits. Ourexperiments went beyond previous research by manipulating information regarding geneticrelatedness, friendship, and potential for future interactions in a complete factorial design,which is more feasible for fictional scenarios than actual interactions. These are the mostimportant variables influencing the evolution of cooperation and altruism according to kinselection theory (and evolutionary game theory (1981; Maynard Smith, 1982). We therefore expected them to have a strong effect on thedesire to altruistically punish and were surprised when they turned out to be statisticallyinsignificant, despite large sample sizes. It is important to emphasize that the altruisticpunishment scenario strongly engaged the interest of the participants, as indicated by theirreported degree of anger, their desire to see the transgressor punished, and the willingness ofat least some of the participants to punish at their own expense. The variables of geneticrelatedness, friendship, and potential for future interactions had no effect despite a strongoverall psychological response.
These results were so surprising to us that we decided to replicate the experiment with minor changes and to add an altruistic helping scenario. The second experiment confirmedthe results of the first experiment with respect to altruistic punishment and demonstrated astrong sensitivity to information regarding genetic relatedness and potential for futureinteractions with respect to altruistic helping, as we originally expected for all forms ofaltruism. Thus, insensitivity to these major variables is not an artifact of our experimentalprocedure but indicates an important psychological difference between altruistic punishmentand altruistic helping, at least in response to fictional scenarios.
We think that this is an important empirical result that demands an explanation, even if the correct explanation is not immediately apparent. We conclude with a brief outline of themajor possibilities in hope of stimulating additional research.
First, our result might be an artifact of using fictional scenarios that have no relevance to real-world interactions. By itself, this possibility is not explanatory because it criticizes anentire method rather than our particular result does. Fictional scenarios are widely used intraditional and evolutionary psychological research and are closely related to questionnairestudies, which are even more widely used. If the method is to be used and trusted at all, itcannot be invoked to distrust a particular result. Moreover, it does not explain any of thedetails of our results, such as the difference between altruistic punishment and altruistichelping. It is clear that all research involving fictional scenarios and questionnaires is mostinstructive in conjunction with studies of real-world interactions and often reveal importantpsychological mechanisms, even when they do not correspond directly to behavior in actualinteractions. In our case, our fictional scenarios are closely related to experiments involvingactual interactions and give comparable results with respect to altruistic punishment,suggesting that the difference between altruistic punishment and altruistic helping is morethan a meaningless artifact. See for a more detailed discussion R. O’Gorman et al. / Evolution and Human Behavior 26 (2005) 375–387 of fictional scenarios as a research method and the importance of narrative in psychologicaland cultural processes.
Second, our result might reflect a mismatch between the modern environment and psychological mechanisms adapted to the ancestral environment, as suggested for altruisticpunishment . One version of the mismatch hypothesis maintains thatall social interactions in the ancestral environment were among genetic relatives andnonrelatives with a high probability of future interactions. Because these were environ-mental constants, humans did not evolve the ability to discriminate and behaveappropriately toward strangers with no possibility of future interactions. Not only is thisclaim implausible, based on what we know about the ancestral social environment et al., 2002; Henrich, 2004), but it is undermined by our experimental results, which showthat people are fully capable of discriminating information regarding genetic relatedness andpotential for future interactions in the context of helping. Moreover, this particular versionof the mismatch hypothesis cannot explain the pronounced individual differences observedin our experiments and previous research involving actual interactions. The mismatchhypothesis cannot be used in its general form to cast doubt on a specific result. A specificversion of the mismatch hypothesis must be proposed that accounts for the experimentalresults in a testable fashion.
Third, our result might be explained in terms of adaptation and natural selection. Moral systems include some rules that are regarded as inviolable and others that are regarded asvoluntary. The Ten Commandments provide examples of rules that are regarded as inviolable.
The commandment bThou shalt not stealQ is not stated with a list of qualifiers such as bexceptfrom a strangerQ or bexcept if you are about to leave the group.Q It has an unconditionalquality similar to the response of our participants to the cheating scenario. Giving to charityprovides an example of a voluntary rule, which is regarded as morally praiseworthy but is notrequired. It is understood that such voluntary acts can be made at the discretion of the actor,similar to the conditional response of our participants to the helping scenario.
Obviously, the so-called inviolable rules are broken in ways that can even be morally justified, such as to avoid a greater moral evil. Nevertheless, the distinction is important,especially at the psychological level, and probably has functional significance as well. Groupswhose members conceptualize at least some rules as unconditional and therefore punishablewhen broken are likely to function better than other groups. To proceed further, it is necessaryto identify the suite of psychological traits that is required for the conceptualization andenforcement of such rules and to see if they can plausibly evolve by natural selection.
Theoretical models devoted to this subject are more recent than the earlier theories of kinselection and reciprocal altruism (although the original paper , on reciprocalaltruism includes relevant verbal discussion), but they are just as important for understandinghuman evolution Boyd, 2001; Sober & Wilson, 1998; Wilson, 2002).
Empirically, has argued that modern hunter–gatherer societies are first and foremost moral communities, with a strong sense of right and wrong that applies toeveryone, regardless of their status. This normative social environment enforced bypunishment creates a degree of behavioral uniformity within groups and differences among R. O’Gorman et al. / Evolution and Human Behavior 26 (2005) 375–387 groups (when they abide by different norms) that is highly favorable for the genetic andcultural evolution of within-group cooperation. It is precisely the traits associated with theconceptualization and enforcement of moral rules that expand the circle of cooperationbeyond genetic relatives and narrow reciprocators, causing human evolution to embark upona different trajectory than all other primate species.
To summarize, altruism can take place in the context of punishment in addition to helping behaviors. Altruistic punishment has been empirically demonstrated in humans inexperiments involving actual interactions. Our experiments reveal a remarkable insensi-tivity to information regarding genetic relatedness, friendship, and potential for futureinteractions in the impulse to altruistically punish, in contrast to the impulse to altruisticallyhelp, at least in terms of the psychological response to fictional scenarios. This result isdifficult to explain in terms of kin selection and narrow reciprocal altruism, but it isplausible in terms of the psychological traits associated with moral systems. Any humantrait revealed by an experiment can potentially be explained as a methodological artifact,as a nonadaptive byproduct, or as an adaptation. We think that the phenomenon of al-truistic punishment and its unconditional nature is most likely to be explained as part of asuite of psychological traits associated with moral systems that is very much a product ofnatural selection.
We thank R. Boyd, S. Bowles, A.B. Clark, E. Fehr, D. Fessler, H. Gintis, P. Richerson, and the EEB group at Binghamton University for helpful discussion.
Appendix A.1. The following is one version of the questionnaire used in Experiment 1 This survey is part of a study on human social behavior. It will require approximately five minutes of your time, which is greatly appreciated. Your participation is strictly voluntary.
Please read through Part I and then turn the page over to complete Part II.
Part I. Try to imagine yourself as part of the following story and then answer the questions Suppose that you and nine friends [cousins] in your town decide to pool your money to invest in the stock market. Pooling the money allows the group to qualify for lowertransaction costs than if each person invests separately. [Alternative for stranger condition:Suppose that you decide to join an investing club in your town whose members pool theirmoney to invest in the stock market. Pooling the money allows the group to qualify for lowertransaction costs than if each person invests separately. Ten people join the club, none ofwhom knew each other previously.] Each person agrees to contribute US$1000 to the pooland to equally share the profits or losses.
The stocks do very well and triple in value after only one year. Just before you meet to divide the profits, you discover that the person who volunteered to keep the books only R. O’Gorman et al. / Evolution and Human Behavior 26 (2005) 375–387 invested US$200, changing the records so that others would not notice. You do somecalculations and determine the following facts: 1. The total amount invested was US$9200 which tripled in value to US$27,600.
2. This was divided equally among all 10 friends [cousins/individuals] to yield US$2760 3. The person who contributed US$200 should have received only US$600 and therefore received US$2160 more than deserved.
4. Everyone else should have received US$3000, or US$240 more than they actually got.
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Boyd, R., Gintis, H., Bowles, S., & Richerson, P. J. (2003). The evolution of altruistic punishment. Proceedings of the National Academy of Sciences of the United States of America, 100, 3531 – 3535.
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