It may be time for us to reconsider what we mean by "rational decisions."  At Project Syndicate, Robert Shiller celebrates the growing influence of neuroscience on economic studies.  Shiller says we are "at the dawn of 'neuroeconomics,'" wherein we are just beginning to gain valuable insights into how people make decisions.

Another direction that excites neuroscientists is how the brain deals with ambiguous situations, when probabilities are not known, and when other highly relevant information is not available. It has already been discovered that the brain regions used to deal with problems when probabilities are clear are different from those used when probabilities are unknown. This research might help us to understand how people handle uncertainty and risk in, say, financial markets at a time of crisis.

John Maynard Keynes thought that most economic decision-making occurs in ambiguous situations in which probabilities are not known. He concluded that much of our business cycle is driven by fluctuations in “animal spirits,” something in the mind – and not understood by economists.

Of course, the problem with economics is that there are often as many interpretations of any crisis as there are economists. An economy is a remarkably complex structure, and fathoming it depends on understanding its laws, regulations, business practices and customs, and balance sheets, among many other details.

Yet it is likely that one day we will know much more about how economies work – or fail to work – by understanding better the physical structures that underlie brain functioning. Those structures – networks of neurons that communicate with each other via axons and dendrites – underlie the familiar analogy of the brain to a computer – networks of transistors that communicate with each other via electric wires. The economy is the next analogy: a network of people who communicate with each other via electronic and other connections.

Read The Neuroeconomics Revolution here.