In this unit, students examine just how amazing the gift of large-scale human cooperation has been for life on earth and why it can be so challenging at times. This unit culminates in a social experiment where students select a goal they have to make society better starting local and then design a rigorous randomized control trial to see what actually works best to achieve that goal. Is it better to build a data-supported analytic argument or write a poem to change someone's mind? How can we really find out?