Please stop saying that it is.
It isn’t. I don’t care who you heard it from, that person has no data to back it up. None. Really. This claim is based on no research ever conducted and no statistics ever collected. It is not based on anyone’s observations or expertise. It. Isn’t. True.
I think claims like this are both sloppy and dangerous.
Neil Brodie and I untangle the mess of this zombie statistic, this factoid in a new FREE/OPEN ACCESS article in Antiquity, available here: https://doi.org/10.15184/aqy.2023.90
Like the archaeologists we are, we excavated this claim down but never hit bedrock. Track your facts back people, all the way to real research. If you can’t track it back, don’t repeat them.
Heard someone making this claim? Send them the link to the paper. Or if you are more social media inclined, send them one of these handy graphics I’ve made, your free to use them: