In a grim time in our history, people were killed to serve as a religious sacrifice for certain events, such as the death of a chief, preparation for war, construction of new house or canoe, epidemic outbreaks and violations of major social taboos.

But a new study suggests that human sacrifices were not only meant for religious purposes.

The research revealed that human sacrifices were also used to build and uphold social classes, to allow the powerful to retain power and keep everyone else in line.

The new study, published in the journal Nature, involves the analyses of 93 traditional Austronesian societies.

Austronesian, according to lead author Joseph Watts, is a large family of languages that originated in Taiwan and migrated as far as Madagascar, Easter Island and New Zealand.

The Austronesian cultures used in the study are very diverse, ranging from the small, egalitarian-based, family-oriented communities of Isneg in the Philippines to the huge complex societies in the Hawaiian Islands.

In a report from the Conversation, researchers found out that 43 percent of the cultures included in the study performed human sacrifices.

The cultures were divided into three depending on their level of social stratification: the "egalitarian," or those with no inheritance of wealth and status between generations; "moderately stratified," or whose wealth and status are inherited but not necessarily linked to higher social classes and "highly stratified," or whose inherited status is strictly imposed.

Researchers used the phylogenetic analysis to determine if the relationship between human sacrifice and social stratification is causal.

They discovered that human sacrifices are more strictly observed in cultures with complex social structure than the egalitarian-based cultures.

According to a Washington Post report, 65 percent of the 27 "highly stratified" cultures in the study committed ritual killings, while only 25 percent of the 20 "egalitarian" cultures practiced human sacrifices.

On the other hand, out of the 46 "moderately stratified" cultures, 37 percent practiced human sacrifices.

In conclusion, researchers said that religious rituals, such as human sacrifices, have played a "darker" role in the development of modern hierarchal societies. These rituals were used by those in position in order to impose social control.