I'd have to say it's a hormone thing. Women can be more risk-takers than men if they have enough testosterone. I don't, and my husband is a great driver, but boy howdy am I the fixer-upper around the cars. And we have great communication. When he last did something stupid and dangerous, I asked him what was the absolute worst-case thing that could happen? And then I asked him how he would feel if that absolute worst-case thing had happened to ME?
He looked stricken. Never did that again. Our love is strong enough to keep both of us from hurting the other. Sorry, pukey-sweet I know but true.
He outgrew the 'hey lookit me mom!' stage a long time ago, and besides, he's a BIG DOG. They don't have to prove anything to anyone. Least of all themselves.
WOOF.