Social inequality began during the Stone Age, according to a study. An international team of archeologists has discovered that hereditary inequality or social inequality began over 7,000 years ago in the early Neolithic era. Archeologists discovered this when they were analysing 300 human skeletons from sites across central Europe.

Strontium isotope analysis of the skeletons, which provides indications of place of origin, found that the Neolithic farmers who were buried with the tools had better land than those who were buried without them.

"The men buried with adzes appear to have lived on food grown in areas of loess, the fertile and productive soil favoured by early farmers. This indicates they had consistent access to preferred farming areas," said Professor Alex Bentley, Professor of Archaeology and Anthropology at the University of Bristol, in a statement.

The study, using strontium isotope analysis, also found that patriarchal society existed during that period. The scientists found that Neolithic women, whose bodies were found in those areas, actually had originated in some other area, probably a different clan. This is a strong indication of patrilocality, a male-centred kinship system where females move to reside in the location of the males when they marry.

This new evidence from the skeletons is consistent with other archaeological, genetic, anthropological and even linguistic evidence for patrilocality in Neolithic Europe. The results have implications for genetic modelling of how human populations expanded in the Neolithic, for which sex-biased mobility patterns and status differences are increasing seen as crucial.

"Our results, along with archaeobotanical studies that indicate the earliest farmers of Neolithic Germany had a system of land tenure, suggest that the origins of differential access to land can be traced back to an early part of the Neolithic era, rather than only to later prehistory when inequality and intergenerational wealth transfers are more clearly evidenced in burials and material culture," said Professor Bentley.

"It seems the Neolithic era introduced heritable property (land and livestock) into Europe and that wealth inequality got under way when this happened. After that, of course, there was no looking back: through the Bronze Age, Iron Age and Industrial era wealth inequality increased but the 'seeds' of inequality were sown way back in the Neolithic," he added.