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Behavioral transition with age in social dilemmas: from reciprocal youth to persistent response in adulthood

Behavioral transition with age in social dilemmas:
From reciprocal youth to persistent response in adulthood

While human societies are extraordinarily cooperative in comparison with other social species, the question of why we cooperate with unrelated individuals remains open. Although much experimental studies have been performed to elucidate several questions related to the emergence and evolution of cooperation in humans, little has been done regarding how cooperativeness changes across our lifetime. This work reports results of a lab-in-the-field experiment with people of different ages in a social dilemma. We found that the average amount of cooperativeness is independent of age except for the elderly, who cooperated more, and a behavioral transition from reciprocal, but more volatile
behavior to more persistent actions towards the end of adolescence. Although all ages reacted to the cooperation received in the previous round, young teenagers mostly responded to what they saw in their neighborhood regardless of their previous actions. Decisions then became more predictable through midlife, when the act of cooperating or not was more likely to be repeated. Our results show that mechanisms such as reciprocity, which is based on reacting to previous actions, may promote cooperation in general, but its influence can be hindered by the fluctuating behavior in the case of children.

M. Gutiérrez-Roig, C. Gracia-Lázaro, J. Perelló, Y. Moreno, and A. Sánchez, “Behavioral transition with age in social dilemmas: From reciprocal youth to persistent response in adulthood”, Nature Communications 5:4362, doi:10.1038/ncomms5362 (2014).

Dynamic Networks & Reputation

Dynamic Networks and Reputation
reputation

Cooperativeness is a defining feature of human nature. Theoreticians have suggested several mechanisms to explain this ubiquitous phenomenon, including reciprocity, reputation, and punishment, but the problem is still unsolved. Here we show, through experiments conducted with groups of people playing an iterated Prisoner’s Dilemma on a dynamic network, that it is reputation what really fosters cooperation. While this mechanism has already been observed in unstructured populations, we find that it acts equally when interactions are given by a network that players
can reconfigure dynamically. Furthermore, our observations reveal that memory also drives the network formation process, and cooperators assort more, with longer link lifetimes, the longer the past actions record. Our analysis demonstrates, for the first time, that reputation can be very well quantified as a weighted mean of the fractions of past cooperative acts and the last action performed. This finding has potential applications in collaborative systems and e-commerce.

J. A. Cuesta, C. Gracia-Lázaro, A. Ferrer, Y. Moreno, and A. Sánchez, “Reputation drives cooperative behaviour and network formation in human groups”, Scientific Reports 5:7843, doi:10.1038/srep07843 (2015)..