Guala's primary contention is that experimental evidence of reciprocity, particularly negative reciprocity, does not necessarily reflect what happens in the real world. This criticism of the “wide reading” of strong reciprocity does not challenge the “narrow reading,” which suggests that social preferences motivate cooperation and punishment in the lab. In making his case, Guala appears to take social preferences for granted, and he does not wonder where they came from and what purpose they serve. Looking at other species will tell us something about the evolutionary history of social preferences and their possible adaptive value.
It is unlikely that the appearance of social preferences in the lab is artifactual. Concern for the welfare of others is one of the mechanisms that motivate our social behaviours. Much has been written about the role of empathy in motivating altruistic acts (Batson Reference Batson1991). Feeling sad at the misfortunes of others and sharing their joy will provide short-term emotional benefits for acts that are otherwise costly when they are performed. Tangible benefits such as reciprocity or reputation are not the primary goals of the altruist. The same case can be made for the other “fortunes-of-others” emotions (Ortony et al. Reference Ortony, Clore and Collins1988), namely, jealousy (unhappiness at the good fortunes of others) and schadenfreude (pleasure in the misfortunes of others). These emotions can bridge the motivational gap between punitive and spiteful acts and any delayed or indirect benefits (e.g., reputation). As Guala points out, the laboratory environment allows for the detection of these preferences. It is possible that in the field, other preferences (such as for reputation) and alternative options (such as ostracism and other less costly forms of punishment) overshadow social preferences. But this in no way implies that these preferences do not exist, nor that they played no role in the evolution of human sociality.
A comparative approach can be helpful in illuminating just how important social preferences are. Guala rightly advocates a comparative anthropological approach. Extending this approach to animals is drawing attention to just how special social preferences might be. Animals do behave altruistically and punitively in the wild (and in captivity). Or, at least, they appear to. For instance, they share food with others (de Waal et al. Reference de Waal, Luttrell and Canfield1993) and punish non-cooperators (Hauser Reference Hauser1992). However, the benefits are likely immediate rather than delayed, casting social preferences in doubt: Food sharing, at least in chimpanzees, can be explained by surrendering to begging pressure (Gilby Reference Gilby2006), and punishment of failure to give food calls is likely due to conflicts over contested food (Gros-Louis Reference Gros-Louis2004).
The approaches taken by experimental economists are being adapted for other animals. An adaptation of the dictator game has one animal choose between one of two food trays, resulting in mutually beneficial outcomes (1/1) as opposed to purely selfish ones (1/0), or altruistic outcomes (0/1 vs. 0/0). Chimpanzees do not show anything resembling a prosocial preference in these studies. Results for cooperatively breeding primates such as cottontop tamarins are mixed (for reviews, see Silk & House Reference Silk and House2011; Jensen, in press). It may be that the competitive nature of chimpanzees in feeding contexts interferes with prosociality. Yet, when given a choice between an altruistic outcome or a spiteful one, chimpanzees remain indifferent (Jensen et al. Reference Jensen, Hare, Call and Tomasello2006). Furthermore, while they will retaliate against harmful actions – namely, theft of their food – they do not respond spitefully to unfair outcomes (another chimpanzee eating food taken from the subject by the experimenter; Jensen et al. Reference Jensen, Call and Tomasello2007a). The latter study is similar in spirit to a money-burning game in which people will forfeit money (in the lab) to see someone else suffer a cost (Zizzo & Oswald Reference Zizzo and Oswald2001).
The Ultimatum Game, as described by Guala, is a widely used tool for testing social preferences in response to unfairness. A reduced form of the Ultimatum Game pits rejections of unfair outcomes (80/20) against alternatives that are either fair (50/50), generous (hyper-fair: 20/80), no different (80/20) and very unfair (hyper-unfair: 100/0) (Falk et al. Reference Falk, Fehr and Fischbacher2003). The results in the lab suggest that rejections are due to a sensitivity to both unfair outcomes and unfair intentions (Falk & Fischbacher Reference Falk and Fischbacher2006). When chimpanzees were confronted with a similar dilemma, proposers did not choose fair outcomes and responders accepted all nonzero offers (Jensen et al. Reference Jensen, Call and Tomasello2007b). Chimpanzees, at least, appear to behave like rational maximizers in the sense that they are indifferent to unfair outcomes. Social preferences do not seem to play a role in punitive and spiteful behaviours in our closest living relatives (Jensen Reference Jensen2010; Jensen & Tomasello Reference Jensen, Tomasello, Breed and Moore2010).
Third-party punishment is only fleetingly mentioned by Guala, despite its possible importance in the real world. Self-interested (second-party) punishment, rather than altruistic punishment, may be important in small-scale societies (Marlowe & Berbesque Reference Marlowe and Berbesque2008). Yet third-party punishment does appear to play a role in maintaining cooperation, even in the absence of institutionalised or collective punishment (Henrich et al. Reference Henrich, McElreath, Barr, Ensminger, Barrett, Bolyanatz, Cardenas, Gurven, Gwako, Henrich, Lesorogol, Marlowe, Tracer and Ziker2006). Social preferences that govern punishment of behaviours that affect us personally can extend to other individuals, and from this, allow for the emergence of rules that ought to apply to others (norms). How these sensitivities evolved is poorly understood. Looking for third-party punishment in other animals in experimental contexts will inform the debate on the role of social preferences in our sociality and help us decide whether strong reciprocity can be widely read.
Results from experiments on animals provide a contrast to the results of experiments on humans. Concern for outcomes affecting others does play a role in guiding social choices for humans – and possibly only humans – in the lab. It would be surprising if such robust experimental findings whither in the light of the real world.
Guala's primary contention is that experimental evidence of reciprocity, particularly negative reciprocity, does not necessarily reflect what happens in the real world. This criticism of the “wide reading” of strong reciprocity does not challenge the “narrow reading,” which suggests that social preferences motivate cooperation and punishment in the lab. In making his case, Guala appears to take social preferences for granted, and he does not wonder where they came from and what purpose they serve. Looking at other species will tell us something about the evolutionary history of social preferences and their possible adaptive value.
It is unlikely that the appearance of social preferences in the lab is artifactual. Concern for the welfare of others is one of the mechanisms that motivate our social behaviours. Much has been written about the role of empathy in motivating altruistic acts (Batson Reference Batson1991). Feeling sad at the misfortunes of others and sharing their joy will provide short-term emotional benefits for acts that are otherwise costly when they are performed. Tangible benefits such as reciprocity or reputation are not the primary goals of the altruist. The same case can be made for the other “fortunes-of-others” emotions (Ortony et al. Reference Ortony, Clore and Collins1988), namely, jealousy (unhappiness at the good fortunes of others) and schadenfreude (pleasure in the misfortunes of others). These emotions can bridge the motivational gap between punitive and spiteful acts and any delayed or indirect benefits (e.g., reputation). As Guala points out, the laboratory environment allows for the detection of these preferences. It is possible that in the field, other preferences (such as for reputation) and alternative options (such as ostracism and other less costly forms of punishment) overshadow social preferences. But this in no way implies that these preferences do not exist, nor that they played no role in the evolution of human sociality.
A comparative approach can be helpful in illuminating just how important social preferences are. Guala rightly advocates a comparative anthropological approach. Extending this approach to animals is drawing attention to just how special social preferences might be. Animals do behave altruistically and punitively in the wild (and in captivity). Or, at least, they appear to. For instance, they share food with others (de Waal et al. Reference de Waal, Luttrell and Canfield1993) and punish non-cooperators (Hauser Reference Hauser1992). However, the benefits are likely immediate rather than delayed, casting social preferences in doubt: Food sharing, at least in chimpanzees, can be explained by surrendering to begging pressure (Gilby Reference Gilby2006), and punishment of failure to give food calls is likely due to conflicts over contested food (Gros-Louis Reference Gros-Louis2004).
The approaches taken by experimental economists are being adapted for other animals. An adaptation of the dictator game has one animal choose between one of two food trays, resulting in mutually beneficial outcomes (1/1) as opposed to purely selfish ones (1/0), or altruistic outcomes (0/1 vs. 0/0). Chimpanzees do not show anything resembling a prosocial preference in these studies. Results for cooperatively breeding primates such as cottontop tamarins are mixed (for reviews, see Silk & House Reference Silk and House2011; Jensen, in press). It may be that the competitive nature of chimpanzees in feeding contexts interferes with prosociality. Yet, when given a choice between an altruistic outcome or a spiteful one, chimpanzees remain indifferent (Jensen et al. Reference Jensen, Hare, Call and Tomasello2006). Furthermore, while they will retaliate against harmful actions – namely, theft of their food – they do not respond spitefully to unfair outcomes (another chimpanzee eating food taken from the subject by the experimenter; Jensen et al. Reference Jensen, Call and Tomasello2007a). The latter study is similar in spirit to a money-burning game in which people will forfeit money (in the lab) to see someone else suffer a cost (Zizzo & Oswald Reference Zizzo and Oswald2001).
The Ultimatum Game, as described by Guala, is a widely used tool for testing social preferences in response to unfairness. A reduced form of the Ultimatum Game pits rejections of unfair outcomes (80/20) against alternatives that are either fair (50/50), generous (hyper-fair: 20/80), no different (80/20) and very unfair (hyper-unfair: 100/0) (Falk et al. Reference Falk, Fehr and Fischbacher2003). The results in the lab suggest that rejections are due to a sensitivity to both unfair outcomes and unfair intentions (Falk & Fischbacher Reference Falk and Fischbacher2006). When chimpanzees were confronted with a similar dilemma, proposers did not choose fair outcomes and responders accepted all nonzero offers (Jensen et al. Reference Jensen, Call and Tomasello2007b). Chimpanzees, at least, appear to behave like rational maximizers in the sense that they are indifferent to unfair outcomes. Social preferences do not seem to play a role in punitive and spiteful behaviours in our closest living relatives (Jensen Reference Jensen2010; Jensen & Tomasello Reference Jensen, Tomasello, Breed and Moore2010).
Third-party punishment is only fleetingly mentioned by Guala, despite its possible importance in the real world. Self-interested (second-party) punishment, rather than altruistic punishment, may be important in small-scale societies (Marlowe & Berbesque Reference Marlowe and Berbesque2008). Yet third-party punishment does appear to play a role in maintaining cooperation, even in the absence of institutionalised or collective punishment (Henrich et al. Reference Henrich, McElreath, Barr, Ensminger, Barrett, Bolyanatz, Cardenas, Gurven, Gwako, Henrich, Lesorogol, Marlowe, Tracer and Ziker2006). Social preferences that govern punishment of behaviours that affect us personally can extend to other individuals, and from this, allow for the emergence of rules that ought to apply to others (norms). How these sensitivities evolved is poorly understood. Looking for third-party punishment in other animals in experimental contexts will inform the debate on the role of social preferences in our sociality and help us decide whether strong reciprocity can be widely read.
Results from experiments on animals provide a contrast to the results of experiments on humans. Concern for outcomes affecting others does play a role in guiding social choices for humans – and possibly only humans – in the lab. It would be surprising if such robust experimental findings whither in the light of the real world.