A very nice read, describing the author's work on the psychology of humans, dogs, chimpanzees and bonobos as a window into the history of human evolution. The main theme is that humans self-domesticated to become the cooperative, social and cultural species that we are today. But even if we are much more friendly towards strangers than most other species, we have a strong tendency to classify people in "us" and "them", and this underlies a lot of the problems in human society.
This book is unusual in the genre in that it discusses explicitly some political aspects of the results in this field. However, it does so without reference to the main strands of political philosophy (except for a brief discussion of constitutional government). This is a problem, and makes the analysis weaker than it could be. However, it does try to provide ideas for positive action, and argues for creating arenas for interactions between foes as a means of creating greater understanding and, eventually, concrete friendships between persons, leading to peaceful co-existence. Segregation in various forms is not the way forward.