The proposition of this book, that faith is an evolved human trait, is presented in a largely convincing and easily read way. Unfortunately, as the author himself writes, there is a lack of relevant and reliable data available making it hard to analyse the subject matter in a purely scientific way, so there is a fair amount of assumption although the reasoning is generally sound. The relationship drawn between religion and music, dance, dreams and trance is particularly interesting and resonates with modern dance music culture.
The book loses a star for the chapter entitled 'The Tree of Religion' which is an unnecessary and weak attempt at framing world religions as pure fabrication, which actually adds nothing to the wider proposition. Yes there is interpolation and assimilation of texts and other religions into the local culture, but the author damages the trust in the rest of the book's rationale when he attempts to debunk Islam as some kind of conspiracy where its founder didn't even exists, then asserts it as a matter of fact. This leads the reader to suspect that reference material throughout has been selected to match the hypothesis rather than being looked at objectively. The author does manage to recover but the damage is done.
The rest of the book is an interesting and thought provoking read. It is unlikely to convince hardened creationists or atheists who reject the idea of religion being a contributing factor in their evolution, or survival of species being influenced by group fitness.