Evolving the ingredients for reciprocity and spite

Abstract

Darwin never provided a satisfactory account of altruism, but posed the problem beautifully in light of the logic of natural selection. Hamilton and Williams delivered the necessary satisfaction by appealing to kinship, and Trivers showed that kinship was not necessary as long as the originally altruistic act was conditionally reciprocated. From the late 1970s to the present, the kinship theories in particular have been supported by considerable empirical data and elaborated to explore a number of other social interactions such as cooperation, selfishness and punishment, giving us what is now a rich description of the nature of social relationships among organisms. There are, however, two forms of theoretically possible social interactions-reciprocity and spite-that appear absent or nearly so in non-human vertebrates, despite considerable research efforts on a wide diversity of species. We suggest that the rather weak comparative evidence for these interactions is predicted once we consider the requisite socioecological pressures and psychological mechanisms. That is, a consideration of ultimate demands and proximate prerequisites leads to the prediction that reciprocity and spite should be rare in non-human animals, and common in humans. In particular, reciprocity and spite evolved in humans because of adaptive demands on cooperation among unrelated individuals living in large groups, and the integrative capacities of inequity detection, future-oriented decision-making and inhibitory control.

Cooperation beyond the dyad: on simple models and a complex society

“…What is surprising is that even chimpanzees, which have these abilities, do not exhibit reciprocity under experimental conditions (Melis et al 2008). Hauser et al (2009) argue that it is not the mere presence of the individual abilities that is requisite for reciprocity, but their integration into a single system. Humans have evolved such an integrated system, one that not only regulates reciprocity but that enables spiteful behaviour (e.g.…”

“…To engage in reciprocity, animals require several cognitive skills, including individual recognition, memory of interactions, an ability to quantify costs and benefits, to delay gratification and inequity detection (Hauser et al 2009). What is surprising is that even chimpanzees, which have these abilities, do not exhibit reciprocity under experimental conditions (Melis et al 2008).…”

“…Why then do we not see more examples of reciprocity among 'smart' animals in the wild? Hauser et al (2009) carefully considered this question and concluded that non-human animals lack both the socio-ecological pressures favouring reciprocity and sufficient integration of the cognitive capacities required to engage in score-keeping reciprocity.…”

“…Individuals have access to kin for cooperative interactions in most animal societies and the kind of situations where the fitness value of a given resource alternates between partners (thus favouring reciprocal interactions) is rare (Whitlock et al 2007;Hauser et al 2009). Vampire bats offer an example where the value to individuals of a given resource (blood) can vary over short periods of time and will have differing values for different individuals at a given time.…”

“…To understand this we may have to return to the pre-Axelrod and Hamilton idea of some kind of cognitive limitation on the practice of reciprocity. Hauser et al (2009) have argued that a cognitive adaptation that integrates a range of specific cognitive mechanisms required for score-keeping reciprocity was uniquely favoured in humans because of our unusual socio-ecology. For additional views on this topic, see Brosnan et al (2010) and Melis & Semmann (2010).…”