I don't see how our shame/embarrassment/guilt behavior is too hard for us to see. It's striking how it can be understood, based on the facts of it, as some kind of a 'toe the line' governor or mechanism for keeping the members of our groups in line with the group's way of thinking, feeling, and judging people and other stuff.
That seems to be why it is always most likely to be seen as a behavior that kicks in when a human recognizes in some way (mostly unconsciously) that they have stepped out of line doing (or not doing) something that their group expects of them. I'd guess the key question then is 'Which group am I most worried about being seen by its members as one of their own."
The Republicans at the convention were, basically I think, 'virtue signaling' that they wanted to be seen by Trump and his other supporters as enthusiastic supporters of Trump. Not a chance I can think of that anyone there doing that would have blushed at anything Trump-like, and especially, blushed at Trump himself.
I'd only take what I've said one step further. Whatever you want to call the 'shame/embarrassment/guilt complex' -- if that's even close to a decent name for it (which I doubt it is just as much as you are likely to doubt that Frankenstein) -- I would consider thinking about it as our 'conscience' or our 'moral conscience' in some kind of core or essential way.
I mean, I can't see how human 'conscience' is not -- even if anything beyond it -- just some DNA based role that conscience plays in us as a somewhat accurate guide to how we should come across as socially acceptable to some person or group of people at least momentarily important to us.
That's human nature as stage-set for seeing it in a way that so definitionally makes someone reflexively stomping on its universal snakes -- especially while declaring he or she was resisting an invasion of foreign snakes (for he or she says, "They sure as hell can't be my own snakes! My snakes are better snakes than these snakes!) -- so, so warmly and touchingly bat**** crazy that none of us could ever have come up with such an outlandishly fool's behavior on our own.
Considered in light of at least the above take on it, the routine and daily operations of any human's conscience give a very special meaning to 'evolved as a social species'.
That's my 2 cents on it, paid as usual in cheap wooden tokens representing my fond affection for the human ecosystem in all of us.