It’s a nice belief that societies were fairer, more egalitarian places before the time in which we became too distracted with shiny metal coins. However, more evidence has shed light on the possibility of socioeconomic inequality among Neolithic cultures from 5,000 years ago.

Archeologists at the University of the Basque Country, Spain, and the University of Oxford looked at the remains of 166 individuals found at Late-Neolithic burial sites in north-central Spain dating from around 3,500 to 2,900 BCE. While some of the people in the area were buried in megalithic grave sites, such as the one pictured above, others were buried in caves.

While the researchers say the meaning behind these separate burial practices is “highly ambiguous”, they believe it could indicate some kind of different social status. Their results were published in the journal PLOS One.

Isotopic analysis revealed that these people, both grave and cave burials, were likely from the same community. The team were able to uncover their diet by looking at the distribution of certain stable isotopes and chemical elements within their bones. The analysis showed that these people lived on a diet of wheat, barley, beef, and lamb. Since people buried at both sites returned similar values, it is believed they shared a similar lifestyle and diet, and thus were from the same community.

Yet, there is definitely a distinction between how these two groups were viewed within that one society.

"Using carbon and nitrogen stable isotope analysis of human and animal remains, our study has identified meaningful differences between those buried in caves and megalithic graves in the Late Neolithic of north-central Spain," said researcher Teresa Fernández-Crespo in a statement. "This implies that, despite living in close proximity, these communities had distinct lifeways involving a partitioning of the landscape."

The Neolithic age brought about a huge development of technology, such as the domestication of animals and agriculture, that likely encouraged shifts in social structure. Archeologists believe this shift from hunter-gatherer peoples to farmers could explain the origins of social stratification. Previously, however, there’s not been too much in the way of physical evidence to back up this claim.