The final in the four-part series shows what the theories, research and science all add up to. It examines the evidence that illustrates how wrong most people in thinking the world is descending into darkness and chaos, and shows instead that it's actually improving at an astonishing rate.

Why are humans neither 'good' nor 'bad'? How can so much chaos and confusion in the world actually lead to order? Why are we so often wrong when we're asked if the world's getting better? In this, the last book in The Secrets of Life quartet, SS O'Connor pulls together the threads of genetic and cultural evolution, and then adds to these the conclusions of evolutionary game theory. As he does this, he ends with an intertwined narrative that explains why so many of the phenomena of our existence may not be the mysteries we think they are, but could in fact have the same underlying logic to them. By examining the great currents at work in our collective story, the role that competition and cooperation have always played in the development of the world, and why each behavioural strategy is rational in what it's attempting to achieve, the book shows that the same cycles of collaboration and destruction have been present since time began. But while the success of these strategies may ebb and flow, it is their interaction that results in the balance and order we see around us. This current is also the consistent vector of our human history. Although we may have animal origins, and are also driven by the same need to respond to the profound Laws of Thermodynamics, we have developed our culture to the point where we can now choose to overrule so many of the instructions of our genes. Why do we do this? What are the problems that arise from our free will? How have we come to realise that self-interest is quite different from selfishness? Why have we become obsessed with the need for fairness and trust in our societies? And how have these forces resulted in us making the world a better place? Few of us believe this can be the case. But as the evidence of our progress becomes ever clearer, the series concludes by showing us why we are often wrong in our view of each other, and why we're so frequently mistaken in our pessimism about the future.