Natural Selection and making lots and lots of money

So, an article in the NYT In Dusty Archives, covers a new book out by Gregory Clark at UC-Davis that posits that the explanation for the accumulation of wealth in eighteenth and nineteenth-century Britain is evolution--that the British population evolved into one that had the culture and knowledge to save money, to work hard, and learn to read.

Basically, his argument boils down to this. The agrarian sector, made of of poorer people, had fewer descendents (having fewer children that lived). Middle-class people had more children that lived and therefore gave more to the human gene pool. And these middle-class English, Scottish, Welsh and Irish transmitted their values and knowledge.

“Thrift, prudence, negotiation and hard work were becoming values for communities that previously had been spendthrift, impulsive, violent and leisure loving,” Dr. Clark writes.

This worries me. We live in a phenomenally wealthy culture, by historical standards. The gap between the rich and poor is growing. Mortality rates are changing to reflect this gap.

What are we passing on?