[1] In response, current work on strong reciprocity is focused on developing evolutionary models which can account for this behavior.
[2][3] Critics of strong reciprocity argue that it is an artifact of lab experiments and does not reflect cooperative behavior in the real world.
If a participant is trying to maximize their payoff, the rational solution (nash equilibrium) for the allocator to assign nothing to the recipient.
In the ultimatum game, the recipient has the choice to either accept the offer or reject it, resulting in both players receiving nothing.
However, experimental results show that participants are willing to pay to punish those who deviate from the average level of contribution – so much so that it becomes disadvantageous to give a lower amount, which allows for sustained cooperation.
[10][11] Modifications of the dictator game and prisoner's dilemma provide support for the willingness to engage in costly third party punishment.
Controlling for a number of other possible influences, Fehr and Leibbrandt demonstrated a positive relationship between hole size and contributions in the public goods game experiment.
[13] Rustagi and colleagues were able to demonstrate a similar effect with 49 groups of Bale Oromo herders in Ethiopia, who were participating in forest management.
[14] In addition to experimental results, ethnography collected by anthropologists describes strong reciprocity observed in the field.
Records of the Turkana, an acephalous African pastoral group, demonstrate strong reciprocity behavior.
If someone acts cowardly in combat or commits some other free-riding behavior, the group confers and decides if a violation has occurred.
Importantly, the age cohort taking the risks are not necessarily those who were harmed, making it costly third party punishment.
[2] In 2004, Samuel Bowles and Gintis presented a follow up model in which they incorporated cognitive, linguistic, and other capacities unique to humans in order to demonstrate how these might be harnessed to strengthen the power of social norms in large scale public goods games.
[20] An important aspect of this model is that strong reciprocity is self-regarding when rare in the population, but may be altruistic when common within a group.
[21] This study was then repeated with a different 15 small scale societies and with better measures of market integration, finding a similar pattern of results.
[23] A particularly prominent criticism of strong reciprocity theory is that it does not correspond to behavior found in the actual environment.
[28] The existence of strong reciprocity implies that systems developed based purely on material self-interest may be missing important motivators in the marketplace.
Strong reciprocity and models based on it suggest that this can be explained by people's willingness to act fairly, even when it is against their material self-interest.
Experimental results suggest that this is indeed the case, with participants preferring less complete contracts, and workers willing to contribute a fair amount beyond what would be in their own self-interest.
Joint ownership of property can be very similar to the public goods game, where owners can independently contribute to the common pool, which then returns on the investment and is evenly distributed to all parties.