Our civilization is facing substantial risks and a growing realization of how climatological ecological tipping points can fundamentally change the premises for life. This rapidly emerging reality compels shift in scope concern humans. Even so, it remains unclear whether our ability to learn, collaborate, address complex problems compatible with this endemic crisis. Here, we existential dilemma...

This article investigates the determinants of generosity in an experiment on charity to real-life welfare recipients. It tests the effects of various measures of unconditional altruism and conditional or reciprocal altruism. The results show strong support for conditional or reciprocal altruism. However, people who are self-reported unconditional altruists make offers that are highly elastic wi...

Animal behavior is often altruistic. In the frame of the theory of natural selection, altruism can only exist under specific conditions like kin selection or reciprocal cooperation. We show that reciprocal cooperation, which is generally invoked to explain non-kin altruism, requires very restrictive conditions to be stable. Some of these conditions are not met in many cases of altruism observed...

Evolutionary theorists have long been interested in the conditions that permit the evolution of altruistic cooperation. Recent work has demonstrated that altruistic donation can evolve in surprisingly simple models, in which agents base their decisions to donate solely on the similarity of evolved "tags" relative to evolved tag-difference tolerances. There is disagreement, however, about the co...

The purpose of this study was to identify personality characteristics associated with kin altruism and reciprocal altruism, and to relate those characteristics to the Big Five personality dimensions. We hypothesized that traits such as empathy and attachment mainly facilitate kin altruism, and that traits such as forgiveness and non-retaliation mainly facilitate reciprocal altruism. Self-report...

The altruism of insect workers has puzzled researchers for decades. Inclusive fitness theory suggests that high relatedness has been key in promoting such altruism. Recent theory, however, indicates that the intermediate levels of relatedness found within insect societies are too low to directly cause the extreme altruism observed in many species. Instead, recent results show that workers are f...

We study the spatial adaptive dynamics of a continuous trait that measures individual investment in altruism. Our study is based on an ecological model of a spatially heterogeneous population from which we derive an appropriate measure of fitness. The analysis of this fitness measure uncovers three different selective processes controlling the evolution of altruism: the direct physiological cos...