"The book gives an excellent multi- and trans-disciplinary overview over this highly debated issue. It is structured in three major parts. Firstly, the reader gets an introduction into the patterns of cooperation among non-human animals and the behavioral ecology of cooperation. The next section reviews the experimental evidence identifying behavior which may be described as strong reciprocity and provides theoretical models of how such a behavior may have evolved. The final five chapters deal with the economic and political relevance of this issue and capture a wide variety of issues. This structure of the book provides an excellent navigation through related topics stemming from different disciplines and makes it easy for the reader to gain insights into this trans-disciplinary research agenda. It also allows to read the book selectively. [...] There is definitely no doubt that the book is worth reading. It is an excellent introduction to the ‘‘puzzle of human cooperation’’ and a superb synopsis of the experimental and theoretical insights in strong reciprocity. However, the book remains relatively silent about other powerful explanations of human cooperation in social dilemmas, e.g., indirect reciprocity."

"The contributors to the current volume propose an alternative mechanism for sustaining cooperation in essentially one-shot interactions. They label this 'strong reciprocity' which is defined as the predisposition to cooperate with others and to punish (at personal cost, if necessary) those who violate cooperative norms even when it is implausible to expect that those costs will be recouped at a later date. They argue that strong reciprocators are conditional co-operators (who behave altruistically as long as they believe that others will do so as well) and altruistic punishers (who apply sanctions to those who violate implicit social norms even at a personal cost to themselves). [...] This is a superb collection that not only provides a comprehensive overview of the evidence in favour of strong reciprocity and how it could have evolved, but also extends the discussion to look for evidence of strong reciprocity among small-scale societies of hunter-gatherers as well as non-human primates and then goes on to examine the implications of strong reciprocity for public policy. However in making their case the editors of the volume adopt a broad-minded stance and there is no party-line here. Contributors to the volume do not always agree about the interpretation of evidence and provide alternative views on occasions. But the result is a volume that is bound to be thought provoking and should be essential reading for all researchers interested in questions of social norms and human cooperation across disciplinary boundaries."