From discovery.com: Ancient Graves Suggest Human Sacrifice.

Physically disabled people may have been ritually sacrificed by European hunter-gatherer tribes as early as 24,000 years ago, according to an investigation into burials from the Upper Paleolithic period.

Well known in large, stratified ancient societies, ritual human sacrifice has never been apparent in the archaeological data of Upper Paleolithic Europe (about 26,000 to 8,000 B.C.).

But, according to lead study author Vincenzo Formicola of the University of Pisa in Italy, several of these burials suggest that human sacrifices may have been an important ritual activity in this period.

"Our findings show that the Upper Paleolithic hunter-gatherers developed a complex system of beliefs, symbols and rituals that are unknown in small groups of modern foragers," Formicola told Discovery News. [continue]