The first one is a toughy, but I think men and women equally brag. We just brag about different things...
I'm a guy and I know for a fact that I act differently around the guys than when I'm with my girlfriend. When I'm with my girl I talk a little softer. When I'm with my friends it doesnt matter what I say or how I say it.
Girls think they know guys and how they think. But only guys know guys and how they think. Just like I have NO clue what my girlfriend is thinking at any given moment. Her brain is ALWAYS ticking and she's always thinking about something. I could be watching tv or driving and be thinking about absolutely nothing. I dont think its possible for my gf to do that. Just my two cents...