This book studiously avoids the plethora of conjectural theories and poorly substantiated opinionation on which so much psychological and sociological research depends. Instead, it reverts to the bedrock evidence of human history, and prehistory as mirrored in primatology, to construct a succinct and very user friendly text which teenagers, parents and aspiring global citizens can readily understand. A more astute and widely assimilated comprehension of human behaviour is key to the solution of the majority of outstanding human problems.