Personal trust extends cooperation beyond trustees: A Mexican study.

We studied 2 groups of workers from Oaxaca (Mexico) with different levels of income and education to investigate the role that the affective-based psychological mechanism of personal trust, as evolutionarily acquired, plays on group cooperation. We measured trust levels through some questionnaires and cooperative behaviour through an iterated prisoner's dilemma under different conditions and analysed trust networks of group members. While these groups did not differ in trust levels or cooperation among trustees, they did differ in terms of cooperation with other group members. Such differences are related to dissimilarities in the trust network topology-as a measure of group cohesion. These results suggest that some personal trust networks extend cooperation within a group beyond trustees in a way that complements the role of the reputation for indirect reciprocity.

Trust-based altruism facing new contexts: The Vyegwa-Gika pygmies from Burundi.

The community of Pygmies settled in Vyegwa-Gika provides an exceptional case study to test the role of trust in the evolution of altruism. The Vyegwa-Gika Pygmies were forced to migrate from rainforests to the savanna, changing quickly their environment, culture, and socio-economic situation. Despite the high level of poverty they suffer in this new settlement, we found evidence of strong altruistic attitudes toward trustees when playing an economic game. In addition, Vyegwa-Gika Pygmies keep small personal trust networks despite the fact they share frequent social interactions within the community. These results indicate the great effectiveness of personal trust in fostering altruism, even if the circumstances make it difficult to establish such kind of affective bonds. A theory of the evolution of altruism should therefore also account for the evolution of psychology of trust, as a key element in the process.

Testing the cultural group selection hypothesis in Northern Ghana and Oaxaca.

We examine the cultural group selection (CGS) hypothesis in light of our fieldwork in Northern Ghana and Oaxaca, highly multi-ethnic regions. Our evidence fails to corroborate two central predictions of the hypothesis: that the cultural group is the unit of evolution, and that cultural homogenization is to be expected as the outcome of a selective process.

Deciding to Cooperate in Northern Ghana: Trust as an Evolutionary Constraint Across Cultural Diversity.

The upper-east and northern regions of Ghana offers a unique opportunity to study the influence of evolutionary social dynamics in making cooperation possible, despite cultural differences. These regions are occupied by several distinct ethnic groups, in interaction, such as the Kussasi, Mamprusi, Bimoba, Konkomba, and Fulani. We will report our fieldwork related to how cooperation takes places there, both within each group and among people from the different groups. Methods included personal networks of cooperation (ego networks), interviews and analysis of group contexts. The most important result is that, while each ethnic group may differ in terms of family and clan structure, a similar pattern can be found in all of them, of cooperation structured around small groups of trust-based close relationships. The study suggests that habitual decisions about cooperation are not strategic or self-interested, but instead are based on unconscious processes sustained by the emotional bonds of trust. These kind of emotional bonds are claimed to be relevant from an evolutionary point of view.

Trust matters: a cross-cultural comparison of Northern Ghana and Oaxaca groups.

A cross-cultural analysis of trust and cooperation networks in Northern Ghana (NGHA) and Oaxaca (OAX) was carried out by means of ego networks and interviews. These regions were chosen because both are inhabited by several ethnic groups, thus providing a good opportunity to test the cultural group selection hypothesis. Against the predictions of this approach, we found that in both regions cooperation is grounded in personal trust groups, and that social cohesion depends on these emotional bonds. Moreover, in agreement with Fiske's notion of "evolved proclivities," we also found two distinct kinds of trust networks, one for each region, which vary in terms of the degree of ethnic interrelation. This pattern suggests that social cohesion increases when environmental resources are scarce.

Deciding to cooperate in northern Ghana: trust as an evolutionary constraint across cultural diversity

The upper-east and northern regions of Ghana offers a unique opportunity to study the influence of evolutionary social dynamics in making cooperation possible, despite cultural differences. These regions are occupied by several distinct ethnic groups, in interaction, such as the Kussasi, Mamprusi, Bimoba, Konkomba, and Fulani. We will report our fieldwork related to how cooperation takes places there, both within each group and among people from the different groups. Methods included personal networks of cooperation (ego networks), interviews and analysis of group contexts. The most important result is that, while each ethnic group may differ in terms of family and clan structure, a similar pattern can be found in all of them, of cooperation structured around small groups of trust-based close relationships. The study suggests that habitual decisions about cooperation are not strategic or self-interested, but instead are based on unconscious processes sustained by the emotional bonds of trust. These kind of emotional bonds are claimed to be relevant from an evolutionary point of view (AU)

No disponible

Personal trust increases cooperation beyond general trust.

In this paper we present a new methodology which, while allowing for anonymous interaction, it also makes possible to compare decisions of cooperating or defecting when playing games within a group, according to whether or not players personally trust each other. The design thus goes beyond standard approaches to the role of trust in fostering cooperation, which is restricted to general trust. It also allows considering the role of the topology of the social network involved may play in the level of cooperation found. The results of this work support the idea that personal trust promotes cooperation beyond the level of general trust. We also found that this effect carries over to the whole group, making it more cohesive, but that higher levels of cohesion rely on a particular topology. As a conclusion, we hypothesize that personal trust is a psychological mechanism evolved to make human social life possible in the small groups our ancestors lived in, and that this mechanism persists and plays a role in sustaining cooperation and social cohesion.