June 3rd - What keeps the show on the road?

Although its generally agreed that in order to have a 'sustainable' future (that is one which we can maintain into the future) we must reduce our use of natural resources and our general impact on the planet, I'm going to try to find out more about how our market economies have led us up a dangerous and potentially catastrophic road.  Most importantly:  What it is that keeps the show on the road?
Putting together what I've read in  Tim Jackson's 'Prosperity without growth' and in David Edwards 'Free to be Human' I've come to understand that capitalism, to meet its need for profit and growth, will continually innovate and introduce new products which are not built to last.  This appeals to our human interest in novelty and change and our need to feel part of the social group, to 'fit in', to be sexy, up to date. Out with the old and in with the new.  Tim Jackson refers to this as a 'complex social logic'. David Edwards believes that for growth to continue we must all be kept discontented. If we don't like how we look, how our houses look and the rest we will go out and buy, buy, buy to oil the wheels of the great capitalist economy.
I can't help feeling that we humans are complex creatures and that market capitalism's need for growth appeals to our less appealing side, our need to be top dog and our competitiveness.  Would it really suit market capitalism if we all decided to live our lives more co-operatively and more altruistically, paying less attention to material consumption? Perhaps not ...