About human nature.

In ancient China, tomb raiding was usually done by father and son together; the father and son would go tomb raiding, and finally crawl out of the tomb.
Does everyone know who should be the first to crawl out?
Should it be the father first, or the son first?
For thousands of years, the rules of tomb raiding, lessons learned from blood and tears, have formed such a custom: the father must crawl out first, then the son.
Because if the son crawls out first, he is very likely to push his father down and keep the treasure for himself, but if the father crawls out, generally, he wouldn’t push the son down.
Usually not.