For decades, social scientists based their work on "rational choice theory." Based partly on observations of culture and partly on evolutionary theory, rationalists argued that people generally made logical decisions about their choices in life in order to maximize their chances of positive outcomes. Many people didn't make rational decisions, of course, but they were the failed exceptions who proved the rule. At both the individual and group levels, people behaved rationally by making decisions that would benefit them the most.
But occasionally, the real world imposes on conventional wisdom and academic theory. In 2008, the economic crisis shattered these comfortable assumptions. Those who believed in rational choice theory, and in naturally self-regulating markets, were left befuddled and disillusioned by widespread irrationality. Sometimes, it seemed, people did not behave in a rational manner, even when their own direct interests were at stake.
We already should have known better. While the popping sound of 2008 was louder than usual, it was by no means the first bubble to burst. Alan Greenspan, the former chairman of the Federal Reserve, coined the term "irrational exuberance" in 1996 to explain the inexplicable: why investors continued pouring their money into IT companies that couldn't possibly be worth what their inflated stock prices indicated. Sure enough, reality set in, and the bubble burst four years later.
Yet rationality is a stubborn concept. Does reason rule human nature in our über-modern, globalized age? Many of us assume that it does. But if investors, normally the most clear-eyed and unsentimental of people, were willing to risk their capital and assets on financial arrangements they barely understood, or on tech companies that were overvalued out of all proportion to their actual assets and income, then what does that say about human rationality more broadly? Irrational exuberance would seem to be just as accurate a predictor of human behaviour as rational choice.
Emotion rather than reason, then, is the key to understanding human nature. That at least is the central premise of Jonathan Haidt's absorbing The Righteous Mind, which should come with a warning label: "contents highly addictive." Written in a breezy and accessible style but informed by an impressively wide range of cutting-edge research in the social sciences, evolutionary biology and psychology, The Righteous Mind is about as interesting a book as you'll pick up this year.
Borrowing from the 18th-century Scottish philosopher David Hume, who differed from most other Enlightenment thinkers on this point, Haidt, a professor of psychology at the University of Virginia, says that reason is subservient to emotion. But he goes a step further, and here's where The Righteous Mind becomes really interesting. Again building on Hume, Haidt argues that emotion is the source of morality, and therefore actually superior to reason.
The champions of reason have built a strong case otherwise. Emotion, they say, breeds superstition and conflict, and is a barrier to progress. Worst of all, it breeds religion, and religion breeds intolerance and backwardness. Western thinkers, from the ancient Greeks and French Enlightenment philosophes to Karl Marx, Sigmund Freud and Richard Dawkins, have assumed that modernity, based on reason and science, will inevitably lead to secularization and the decline of religion, which, in turn, will lift humanity to bigger and better things. Secularization theory has become conventional wisdom in the West. Yet around the world, religion shows no signs of abating.
Haidt has an answer for this: Thanks to natural selection, evolution has hard-wired religion, intuition and other emotional and sentimental alternatives to pure reason into our genetic code. In his most frequent metaphor, he compares the psychological interplay between reason and intuition to the relationship between an elephant and its rider. The elephant represents 90 per cent of the relationship, and the rider can't force the elephant to go where it doesn't want to go. Yet the rider can sometimes influence where they're headed. For a variety of reasons peculiar to Europe, Westerners came to give more power to the rider. Still, emotion rules, even in the rational West.
When people believe that something is immoral even if it is harmless – when a man makes love to a dead chicken in the privacy of his own home, to use one of Haidt's many graphic examples – they are morally dumbfounded. They know it's wrong, but they can't explain why.
Haidt argues that we have six moral senses – care, fairness, liberty, loyalty, authority and sanctity – just as we have a sense of taste or touch. Liberals usually only feel the first three, whereas all six resonate with conservatives. This doesn't mean that conservatives are morally superior, but it does mean that it will be nearly impossible to convert others to your cause through an appeal to reason.
The implications of all this are profound and far-reaching, and they help explain why the Western concept of "universal" human rights grounded in individual autonomy is actually foreign to most other cultures (and thus not so universal after all).
This is a troubling thought, and Haidt is not always convincing in explaining it. Though he's careful to disavow homophobia and racism, his admonition to follow the elephant rather than heed the rider could easily be used to justify the suppression of gay rights or multiculturalism.
After all, people are morally dumbfounded by alternative sexualities all the time, but this should not excuse their ignorance and bigotry. But whether one agrees that the elephant knows better than the rider, nobody could doubt the power of emotion and intuition after reading The Righteous Mind.
Andrew Preston teaches history at Cambridge University. His most recent book is Sword of the Spirit, Shield of Faith: Religion in American War and Diplomacy.