Urges us to consider what the cost of progress truly is. If economic growth doesn’t lead to any improvement in our overall quality of life is it really the kind of advancement we want to perpetuate? Ryan takes an approach to human nature that refutes Hobbesian belief that we naturally selfish, miserable creatures. Rather, Ryan believes we are innately generous people that thrive on sharing and reciprocity- but an unnatural civilized world has led us to adopt negative adaptations. We often choose to be self-serving, private, and stingy for the sake of surviving in a manmade environment that deeply contrasts how we should be living. Humans are unique in that we are the only animals that inhabit a zoo of our own design.