Yeah, decidedly oversimplified, but rooted in sound principles.
The purely physical, and thus non-rational, aspect has been covered, so now on to the conscious.
The sociologist Veblen covered the conscious pursuit of prowess in a mate in discussing physical prowess versus pecuniary prowess. He's also the one who gave us the term "conspicuous consumption," or the idea of how people try to both attract mates and show their success in life by spending unnecessarily.
http://www.mnc.net/norway/veblen.html
http://cepa.newschool.edu/het/profiles/veblen.htm