The question is how we know this. English is not a completely uniform language. There are many colloquialisms used in various English speaking countries that are not used in others. Yet I've never heard the phrases in this article said in any different way.
Ya, like the other famous saying: "Born and Bred"............. 'cuseme, but don't you have to be "bred" first before getting "born" ?
As you know. with English, and other languages, but especially English, lots of words have more than one meaning. The 'bred' in born and 'bred' doesn't refer to the act of breeding (sex), but to how the child is raised after it has been born. What a nice young man, he's been bred well. Good breeding will allow her to go places.