What's it called when someone's overly concerned with what other people think and how do they treat it?

[M]

Does it come from passive bullying, like being exposed to gossip-mongers, or is it a born thing like a kind of social anxiety or phobia? Are these kinds of people especially well-suited to public life (because they're always thinking of their reputation) or especially poorly-suited for precisely that purpose?

Does the media create this social sickness to bolster the value of its photos and paparazzi materials and create a market where there should be none?

[Daniel]

It's called social anxiety. Or shyness. They are one and the same thing, although many people who are shy do not have the self-awareness to know that they are anxious.

Some are born with it, it is a survival trait. It's like a shell that we use to protect ourselves. When people are amongst family they are less shy because they feel the shell is not necessary. The media didn't create this behaviour. It's tens of thousands of years old. It does keep us safe and that is why it has survived for so long, passed on from one shy generation to the next.

However it can suffocate our creativity and wit. Only the brave are prepared to improvise. The shy are too scared to improvise and express themselves. Therefore shy people are less successful.