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Effect of resource spatial correlation and hunter-fisher-gatherer mobility on social cooperation in Tierra del Fuego.

Santos JI, Pereda M, Zurro D, Álvarez M, Caro J, Galán JM, Briz i Godino I - PLoS ONE (2015)

Bottom Line: According to ethnographic sources, the Yamana developed cooperative behaviour supported by an indirect reciprocity mechanism: whenever someone found an extraordinary confluence of resources, such as a beached whale, they would use smoke signals to announce their find, bringing people together to share food and exchange different types of social capital.The model provides insight on how the spatial concentration of beachings and agents' movements in the space can influence cooperation.We conclude that the emergence of informal and dynamic communities that operate as a vigilance network preserves cooperation and makes defection very costly.

View Article: PubMed Central - PubMed

Affiliation: INSISOC, Universidad de Burgos, Escuela Politécnica Superior, Edif. "La Milanera", Burgos, Spain.

ABSTRACT
This article presents an agent-based model designed to explore the development of cooperation in hunter-fisher-gatherer societies that face a dilemma of sharing an unpredictable resource that is randomly distributed in space. The model is a stylised abstraction of the Yamana society, which inhabited the channels and islands of the southernmost part of Tierra del Fuego (Argentina-Chile). According to ethnographic sources, the Yamana developed cooperative behaviour supported by an indirect reciprocity mechanism: whenever someone found an extraordinary confluence of resources, such as a beached whale, they would use smoke signals to announce their find, bringing people together to share food and exchange different types of social capital. The model provides insight on how the spatial concentration of beachings and agents' movements in the space can influence cooperation. We conclude that the emergence of informal and dynamic communities that operate as a vigilance network preserves cooperation and makes defection very costly.

No MeSH data available.


Average cooperation and spatial distribution of beached whales.Matrix of plots of the average cooperation <c> as a function of vision v for different spatial distributions of beached whales (columns) and levels of importance of social capital θ (rows), when the agents’ movement is a random walk. The maximum standard error of the average of cooperation of all experiments represented in the plots is 0.056.
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pone.0121888.g007: Average cooperation and spatial distribution of beached whales.Matrix of plots of the average cooperation <c> as a function of vision v for different spatial distributions of beached whales (columns) and levels of importance of social capital θ (rows), when the agents’ movement is a random walk. The maximum standard error of the average of cooperation of all experiments represented in the plots is 0.056.

Mentions: In the next set of experiments, we relax the assumption that beached whales are uniformly distributed over the space and consider other families of distributions closer, or at least more plausible, to the historical distribution of beachings. In particular, we suppose that beached whales follow a 2D Gaussian with the mean placed at the middle of the space and a standard deviation σ that modulates the spatial dispersion of beachings. Fig 7 shows the level of cooperation for a combination of different spatial distributions, i.e. uniform and Gaussians, and levels of importance of social capital θ, when the frequency of beachings Pbw and the visibility of these events v vary. The bottom row of plots corresponding to a uniform distribution is identical to the results showed in Fig 6, and can be used as a benchmark for comparing the effects of the set of Gaussian distributions, with increasing standard deviation σ, whose results are depicted in each of the remaining rows of Fig 7.


Effect of resource spatial correlation and hunter-fisher-gatherer mobility on social cooperation in Tierra del Fuego.

Santos JI, Pereda M, Zurro D, Álvarez M, Caro J, Galán JM, Briz i Godino I - PLoS ONE (2015)

Average cooperation and spatial distribution of beached whales.Matrix of plots of the average cooperation <c> as a function of vision v for different spatial distributions of beached whales (columns) and levels of importance of social capital θ (rows), when the agents’ movement is a random walk. The maximum standard error of the average of cooperation of all experiments represented in the plots is 0.056.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390331&req=5

pone.0121888.g007: Average cooperation and spatial distribution of beached whales.Matrix of plots of the average cooperation <c> as a function of vision v for different spatial distributions of beached whales (columns) and levels of importance of social capital θ (rows), when the agents’ movement is a random walk. The maximum standard error of the average of cooperation of all experiments represented in the plots is 0.056.
Mentions: In the next set of experiments, we relax the assumption that beached whales are uniformly distributed over the space and consider other families of distributions closer, or at least more plausible, to the historical distribution of beachings. In particular, we suppose that beached whales follow a 2D Gaussian with the mean placed at the middle of the space and a standard deviation σ that modulates the spatial dispersion of beachings. Fig 7 shows the level of cooperation for a combination of different spatial distributions, i.e. uniform and Gaussians, and levels of importance of social capital θ, when the frequency of beachings Pbw and the visibility of these events v vary. The bottom row of plots corresponding to a uniform distribution is identical to the results showed in Fig 6, and can be used as a benchmark for comparing the effects of the set of Gaussian distributions, with increasing standard deviation σ, whose results are depicted in each of the remaining rows of Fig 7.

Bottom Line: According to ethnographic sources, the Yamana developed cooperative behaviour supported by an indirect reciprocity mechanism: whenever someone found an extraordinary confluence of resources, such as a beached whale, they would use smoke signals to announce their find, bringing people together to share food and exchange different types of social capital.The model provides insight on how the spatial concentration of beachings and agents' movements in the space can influence cooperation.We conclude that the emergence of informal and dynamic communities that operate as a vigilance network preserves cooperation and makes defection very costly.

View Article: PubMed Central - PubMed

Affiliation: INSISOC, Universidad de Burgos, Escuela Politécnica Superior, Edif. "La Milanera", Burgos, Spain.

ABSTRACT
This article presents an agent-based model designed to explore the development of cooperation in hunter-fisher-gatherer societies that face a dilemma of sharing an unpredictable resource that is randomly distributed in space. The model is a stylised abstraction of the Yamana society, which inhabited the channels and islands of the southernmost part of Tierra del Fuego (Argentina-Chile). According to ethnographic sources, the Yamana developed cooperative behaviour supported by an indirect reciprocity mechanism: whenever someone found an extraordinary confluence of resources, such as a beached whale, they would use smoke signals to announce their find, bringing people together to share food and exchange different types of social capital. The model provides insight on how the spatial concentration of beachings and agents' movements in the space can influence cooperation. We conclude that the emergence of informal and dynamic communities that operate as a vigilance network preserves cooperation and makes defection very costly.

No MeSH data available.