Why "upward socializing"? Because when you go out and hang out with a group of older people ten years older than you at a bar, even if they don't necessarily have more money than you, their age means they are more likely to pay the bill. Additionally, whether they call the waitresses or you call them, most of the time they will be around you because you're the youngest. Don't ask me how I know—because last night I was out with a bunch of guys ten years younger than me, and I became that old guy.