"Years ago, anthropologist Margaret Mead was asked by a student what she considered to be the first sign of civilization in a culture. The student expected Mead to talk about fishhooks or clay pots or grinding stones.
But no. Mead said that the first sign of civilization in an ancient culture was a femur (thighbone) that had been broken and then healed. Mead explained that in the animal kingdom, if you break your leg, you die. You cannot run from danger, get to the river for a drink or hunt for food. You are meat for prowling beasts. No animal survives a broken leg long enough for the bone to heal.
A broken femur that has healed is evidence that someone has taken time to stay with the one who fell, has bound up the wound, has carried the person to safety and has tended the person through recovery. Helping someone else through difficulty is where civilization starts, Mead said."
We are at our best when we serve others. Be civilized.

@pinskal I never liked this claim much because 1) caring for the injured is a general social animal behavior-wolves do this, are wolves a society? Are shrews?
2) despite the lower survival rates, the rate of healed broken long bones isn't zero in non-social animals either https://pubmed.ncbi.nlm.nih.gov/27691945/

"Civilization" is an arbitrary colonial concept, all humans are social animals.

PREVALENCE OF HEALED LONG-BONE FRACTURES IN WILD CARNIVORES FROM THE NORTHEASTERN UNITED STATES - PubMed

Museum specimens representing 12 species of terrestrial carnivores from the northeastern United States were inspected for evidence of healed long-bone fractures. Of 413 individuals, 18 (4.4%) exhibited healed fractures. Thirteen (72.2%) occurred in hind limbs; five (27.8%) occurred in forelimbs. Mus …

PubMed