Frans de Waal says many people believe that "the economy was killed by irresponsible risk-taking, a lack of regulation or a bubbling housing market, but the problem goes deeper. ... The ultimate flaw was the lure of bad biology, which resulted in a gross simplification of human nature," In particular, the reduction of human behavior to one motive, self-interest, is at fault (this is a much shortened version of the original):

How bad biology killed the economy, by Frans de Waal, RSA Journal: ...The book of nature is like the Bible: everyone reads into it what they like, from tolerance to intolerance and from altruism to greed. But it’s good to realize that, if biologists never stop talking about competition, this doesn’t mean that they advocate it, and if they call genes selfish, this doesn’t mean that genes actually are. Genes can’t be any more ‘selfish’ than a river can be ‘angry’ or sun rays ‘loving’. Genes are little chunks of DNA. At most, they are self-promoting, because successful genes help their carriers spread more copies of themselves. ...

[Many people have] fallen hook, line and sinker for the selfish-gene metaphor, thinking that if our genes are selfish, then we must be selfish, too. ... [T]oo many economists and politicians ... model human society on the perpetual struggle that they believe exists in nature, which is actually no more than a projection. Like magicians, they first throw their ideological prejudices into the hat of nature, then pull them out by their very ears to show how much nature agrees with them. It’s a trick for which we have fallen for too long. Obviously, competition is part of the picture, but humans can’t live by competition alone. ...

Lovers of open competition can’t resist invoking evolution. The e-word even slipped into the infamous ‘greed speech’ of Gordon Gekko, the corporate raider played by Michael Douglas in the 1987 movie Wall Street: “The point is, ladies and gentleman, that ‘greed’ – for lack of a better word – is good. Greed is right. Greed works. Greed clarifies, cuts through and captures the essence of the evolutionary spirit.” ... Is the evolutionary spirit really all about greed, as Gekko claimed, or is there more to it?