The distribution of grave goods are a potential indicator of the social stratification of a society. Thus, early Neolithic graves tend to show equal distribution of goods, suggesting a more or less classless society, while in Chalcolithic and Bronze Age burials, rich grave goods are concentrated in "chieftain" graves (barrows), indicating social stratification. It is also possible that burial goods indicate a level of concern and consciousness in regard to an afterlife and related sense of spirituality. For example, when they buried pharaohs in ancient Egypt, they buried common house hold items, food, vehicles, etc. so they could have a comfortable afterlife.