Was good posture the first form of human ettiquette?

Who knows? Why would you think so? it could just as easily (and in fact probably was) a form of greeting ritual.

Ah, well it’s clearly become important. It’s just a discussion about posture…you don’t have to bend over backwards finding an answer..

I don’t think so. We see in a lot of fossils and a lot of existing hunting-gathering-gardening peoples (assuming that they are more or less living as humans have for millenia, which is supported with some exceptions) that basically everyone had/has good posture, without the damages to the knees, hips, and vertebrae that many agricultural and industrial humans have. Good posture just seems like a constant for a lot of them. What we see in terms of etiquette, and what I think is one of the central survival features of the human brain, is the universal custom of gift-giving, which facilitates both relational ties and resource distribution, forming gift economies.

Nice…now lets do some shopping…

I doubt it. Etiquette is about being polite to each other and getting along—the emotional arena. Posture has to do with physical things, not emotional things. Perhaps, over time, some physical things might gain emotional significance, but I really doubt it.

I don’t know about it being related to etiquette but good posture would show a person to their maximum height and show their limbs to their best formed advantage. That in itself is advantageous for attracting the opposite sex as well as physically ranking within your own.