Adapting the body to be more effective. Biological evolution has to do with the replication of genes. What is adaptive is able to replicate itself over time. Cultural evolution has to do with the replication of ideas, Communicable ideas spread-i. e. language, dance some emotions more easily communicated than others, socially acceptable ideas some things people think but would never say out loud, proximity have to access to communicate ideas. Useful ideas spread- unsolicited advice, as providing connection. Emotional ideas spread- common experience than foster bonding. Minimally counterintuitive ideas spread- easier to remember peaks at emotion a little bit. Example: organ harvesting- the element of fear is real because it is feasible, only minimally counterintuitive, whether its true or not continues to be repiecated for a decade. Example of fictional stories being replicated: hunter-gatherer adaptedness: Usually nomadic- moving when resources were unavailable. Daily life involved physical challenge, vigorous exercise.