Although positive reciprocity (reciprocal altruism) has been a focus of interest in evolutionary
biology, negative reciprocity (retaliatory infliction of fitness reduction) has been largely …

The occurrence of cooperation poses a problem for the biological and social sciences.
However, many aspects of the biological and social science literatures on this subject have …

Somewhere in Africa, more than a million years ago, a line of apes began to rear their young
differently than their Great Ape ancestors. From this new form of care came new ways of …

In cooperatively breeding vertebrates, nonbreeding helpers raise young produced by
dominant breeders. Although the evolution of cooperative breeding has often been …

▪ Abstract It has recently been argued that the paradox of hel** behavior in birds has been
solved. This optimism may be premature. I argue that there is no obvious dichotomy …

Animal Traditions maintains that the assumption that the selection of genes supplies both a
sufficient explanation of the evolution and a true description of its course is, despite its …

Humans use punishment to promote cooperation in laboratory experiments but evidence
that punishment plays a similar role in non-human animals is comparatively rare. In this …

Hamilton's inclusive fitness theory represents one of the most important developments in
evolutionary biology. In particular, the idea that individuals benefit from the reproduction of …

In cooperatively breeding superb fairy-wrens (Malurus cyaneus), all males contribute to the
feeding and defence of young. Despite the expectation that such paternal care should be …

Causing harm to others would hardly seem to be relevant to cooperation, other than as a
barrier to it. However, because selfish individuals will exploit cooperators, functional …