Matching your hat to your shoe to your bag, or your necklace to your earrings, has a tendency to look dated. Mixing up your accessories adds interest to an outfit, and can make you look much more modern and polished.
Obama doesn't run around wearing a Carrie Bradshaw-esque nameplate necklace that says 'Socialist.' But his policies, actions, words, background and associations speak louder than any ID necklace ever could.
A big diamond necklace is nouveau riche, really. People who have wealth a long time don't wear such things.
It is true that in France, women put on less things. If they have a necklace, they don't put on earrings; if they have nail polish, they don't put on all their rings and all their bracelets.
My first memory in the world is my gym teacher ripping my mother's necklace off her neck and throwing it out the window and her running downstairs to go after it. I have no memory before that. I was 4. My father had a lot of girlfriends and my mother had a lot of boyfriends.