Tribalism examines human behavior from the perspective of paleoanthropology, evolution, genetics and the neurosciences, as well as the philosophical implications. Tribalism is the collection of genetically inherited behavioral traits which were of survival value to our ancient ancestors yet these traits not only remain vibrant in modern humans but influence human behavior. These genetic traits, fear, aggression, greed, prejudice, compassion and morality influence our decisions concerning interpersonal relations, governance and global warming. Our ancient genetic survival traits may be the causal agent leading humanity towards dire consequences.
This is less a book describing the many aspects of tribalism and more of an exploration of the genetic basis for tribalism, and how that tribalism affects human civilization. The main thrust of the entire book is the author's belief (well supported by scholarly evidence, much cited) that tribalism is the driving force behind the road mankind is on leading to the cliff of extinction. And we have perhaps already passed the point of no return.
There are better books on human psychology, anthropology, neurobiology, genetics, climat change. I know that if you add mayo you can make a decent salad out of anything. This however was not the salad I was hungry for. Also, obnoxiously US-centric.