If you're interested in stuff like this, check out 'How we decide' by Jonah Lehrer : http://www.amazon.com/How-We-Decide-Jonah-Lehrer/dp/06186201...

I'm reading it now, and it's an amazingly insightful book, in that it manages to at once explain the workings of the brain on a psychological and physiological level, for a whole different slew of "decisions" we humans make.