Maybe it’s also that ous vices and physical problems are easier to see. Myopia or an injury or a smoking habit are something you deal with everyday, easy to spot. So it becomes something our brain occupies itself with. Good traits are often things that are only seen under certain circumstances.
Another thought: we’re taught that praising ouselves is bad, humility is a good thing. So what else are we to talk about than who is worse off or doing more stupid things? It might be an acceptable way to brag 😉
Anyway, interesting article and comments.

that goes quite well with what Nancy said in her article too, and I was thinking, about people being proud of their particular vice (you do hear this a lot, like someone bragging about smoking a whole packet of cigarettes a day and someone else saying, ‘ha, that’s nothing, I smoke two!’) I have often wondered why people brag about that kind of thing, but you could be right – they’re ‘proud’ of what they subconsciously perceive as an expression of their energy and strength… lots of food for thought here guys, thanks!