One possible stimulus for conspicuous consumptions is competition for mates, something akin to the birds' mating song and dance. Granted, one might think that a fat checking account and the security that comes with it would act as a more powerful aphrodisiac than a fast (and fast depreciating) car, but then many humans are not that much brighter than birds
I believe you are right about the competition for mates - that is in our genes from the beginning of mankind. The story goes like this: females want the stronger, more virile male (providing comfort and security) so that the children she bears will have a greater chance at survival. More food and better shelter against the elements allows for stronger, healthier children.
I can see that in nature and appreciate it for what it is...
It's probably just me, but there comes a point when the consumption really is conspicuous, and it makes me nervous. Having 8 light switches in one's master bath is just too much for me and having food in the pantry that is years old and dusty because it is never seen or intended to be used just freaks me out.
I incline more towards 'mean, lean, fine machines' that are efficient, lithe and offers many ways to be useful.
Each to his own, I guess... Zen and the art of? 8)
Best,
Akaisha
Author, The Adventurer's Guide to Early Retirement