I will say, aggression emerges when resource is scarce. And I will say that scarcity is a perception before it is the reality of hunger and cold. Then, when a definition of scarcity contains an idea of no color TV, it appears that scarcity also contains an expectation.
Some would argue that a gentler angst would fail to account for an idea of plenty. It's money people want, they'll say, and lots of it. And to the question why? we'll mostly answer, because that's what makes us feel good.