The revolutionary concept first proposed in this book is that the major unit of natural selection is not the individual or the species, but the genes themselves. It explains how the genes are selfish and how they make the organisms behave in a way that will ensure that they survive. The book is written in an accessible and engaging language, where the 'selfish gene' theory is described in such a way that it gives the reader new insight about the evolution, cooperation, and complexity of life with striking examples. It challenges traditional views in that it strongly suggests that actions and the natural world are importantly shaped by our genetic make-up.