Monkey Generosity: No Strings Attached

In my final chapter I point out that altruism need not simply be a product of evolutionary proximity to humans, but that its emergence may depend on the social structure of any species. Primate species that practice allo-parenting, for instance, like marmosets - where the adults cooperate in the raising and care of the kids irrespective of genetic relationship - demonstrate a greater willingness to facilitate access to food for each other than non allo-parenting species which are more likely to be selfish hoarders. This article, based on he research of Charles Snowden's group at the University of Wisconsin-Madison, shows the propensity for forgiveness, or rather perhaps, the erosion of mistrust between cotton-top tamarin pairs, over time, when one of them has been perceived by the other of selfish behaviour. In experiments where one member of the pair can elect to withhold or dole out food to the other member who has wronged them in the recent past, altruistic sharing soon reasserts itself.