It was a practice carried out by many ancient cultures. From the Germanic, Arab, Turkic, and Inuit to the American, Austronesian, African, Chinese, and Japanese cultures—human sacrifice served a variety of purposes.

A new study published in Nature claims the practice may have co-evolved with social class systems, becoming more prevalent in societies with distinct hierarchies. The study is based on the social control hypothesis, which postulates that human sacrifice legitimizes both social class systems and political authority.

The researchers focused their study on 93 traditional Austronesian cultures.

“We found that the extent of social stratification, as well as the presence of human sacrifice, varied throughout a wide range of geographic regions and cultural groups,” the researchers wrote. “Evidence of human sacrifice was observed in 40 of the 93 cultures sampled.”

The practice occurred in 25 percent of the egalitarian societies, 37 percent of the moderately stratified societies, and 67 percent of the highly stratified societies.

“In traditional Austronesian cultures there was a great deal of overlap between religious and secular authority,” study author Joseph Watts, of the University of Auckland, wrote on his website. “Those who were out of favor with social elites often became the victims of human sacrifice. Human sacrifice may have been a particularly effective means of social control because it provided a supernatural justification for punishment.”

Austronesian cultures originated in Taiwan but spread west to Madagascar, east to Rapa Nui, and south to New Zealand.

“Cultures are not independent—they are linked by common descent and historical relationships,” Watts wrote. “Phylogenetic methods account for this non-independence by modeling the evolution of traits on a family tree. This modeling enabled us to infer the direction of causality based on whether human sacrifice arose before or after social stratification.”

Since Watts and colleagues focused their study on Austronesian cultures, questions remain regarding the link to human sacrifice and social hierarchy in other cultures throughout the world.

But according to Watts, Chinese and Egyptian rulers’ graves were often accompanied by pits with hundreds of additional human bodies, and the Aztecs employed human sacrifice to justify authority over various populations.

“Our study suggests that human sacrifice functioned as a stepping-stone to help build and maintain power in early hierarchical societies,” Watts concluded. “Once these social systems developed, the practice was replaced by more formal methods of social control.”