What causes guys to have delusions of grandeur?

Interesting query... Guys, in general, are not grounded in reality the way gals are. Tend to be more narcissistic, dream about flying, being the richest or most powerful around, have a higher self esteem (without justification) than women. When the delusions become large and guy cannot differentiate between thoughts and reality, delusions become part of psychosis (like hitler and many dictators). Testosterone, hmmmmm.
Different pt of view. Men aren't more prone to delusions of grandeur than women; we just live in a world where success is viewed differently for guys vs gals. Men are under more pressure to appear powerful: leader at work, athlete, rich, brilliant, fearless... Women feel expected to look good: perfect body, perfect family, perfect home... We all sometimes show off to impress someone, to cover up our insecurity, etc...