Several of the smashed skulls, all of young men.
Evidence that some Stone Age cultures may have considered dead young men to be threatening to living people could be the reason groups of newly discovered skulls were buried with smashed-in faces.
The 10,000-year-old skulls were found in Syria. They appear to have been dug up several years after being buried with their bodies, separated, then reburied. No one knows why Neolithic societies buried clusters of skulls - often near or underneath settlements.
Like those found in other caches, they have been cleanly separated from their spines, suggesting they were collected from dead bodies that had already begun to decompose. Patterns on the bone indicate that some had been decomposing for longer than others, making it likely that they were all gathered together for a specific purpose.
Most of the skulls belonged to adult males between 18 and 30 years old.