Despite engaging in human sacrifice, the people who lived in the Lambayeque Valley of northern Peru had low levels of violence, a new study of their remains finds.

Human sacrifice occurred in the valley over the millennia. It's thought that at least some of these mass sacrifices were attempts to appease the gods in the wake of El Niño, a periodic weather phenomenon that can lead to intense rains and flooding in Peru and droughts in other parts of South and Central America.