>My expectation is that confidence and grace is evenly distributed at birth, but is added to the physically attractive and denied to the unattractive almost immediately.

I don't think it would be evenly distributed, but it goes something like that. You can choose to behave confidently up to a point, but people reject such behavior from an ugly person. Ignoring this social feedback can get you into a lot of trouble.

>I've always found the physically-unattractive-but-socially-attractive especially interesting because they've succeeded, often along with a very cool peer group.

Some of these are brutal too. I've known some real busted dudes who got attractive girls to like or marry them somehow. I assume it's often money, connections, and/or encountering the right person who is a sucker for your particular characteristics. Imagine being the ugly brother or nephew of a solid 10 (guy or girl), or being a multi-millionaire. You'd easily get many times more opportunities in all areas of life.