Chaos Descending wrote:
I think a FAR better question is "why would an alien custom necessary have to follow any traditional human paradigms?"
I think we have a winner...
And the answer is so that the human, American, 1960s audience will be able to understand, if not relate to, the characters.
As for the Vulcan salute, we all know it originates with the blessing of the Cohanim. What's funny is that many people, like Celia Lovsky, couldn't do it, so someone assisted manually before the cameras rolled, and they just kept their hand in that position and raised it up at the right time.