Book Review

Moral Minds: How Nature Designed Our Universal Sense of Right and Wrong

N Engl J Med 2007; 356:644-645February 8, 2007

Article

Moral Minds: How Nature Designed Our Universal Sense of Right and Wrong
By Marc D. Hauser. 489 pp., illustrated. New York, Ecco, 2006. $27.95. ISBN: 978-0-06-078070-8

Marc Hauser's groundbreaking book advances a new theory of moral judgment, synthesizing a great deal of work in neuroscience, psychology, and ethology, as well as the author's own recent experimental work. Hauser aims to demonstrate that morality is innate in the way that language is innate: not in its precise content, but in its form. Just as, according to Noam Chomsky, each child comes into the world with a brain wired for language acquisition, so is each of us born ready to acquire a moral system, Hauser argues. Just as the innate workings of the human mind tightly constrain the grammar of any possible human language, so do they constrain — without determining — the content of any possible moral system.

In Hauser's view, the moral faculty is triggered by the perception of an action or the omission of an action and automatically produces a judgment that is sensitive to the action's (or omission's) causes and consequences and to whether the consequences were intended or foreseen. Actions are perceived to have more moral weight than omissions, and intended harms are seen to be morally worse than foreseen harms. Using his ongoing Web-based surveys, Hauser has amassed an enormous amount of evidence demonstrating that these distinctions are made in the same way in all cultures, across all educational levels, and by both sexes.

But subjects are typically unable to articulate adequate justifications for their judgments. Hauser takes this inability to be evidence for his view that we have a moral faculty that operates below the level of conscious awareness. Once again he points out the parallels to linguistic competence. Just as it is easy for us to judge whether a sentence is grammatical but difficult for us to justify or explain that judgment, so we are able to judge the permissibility of an action easily but find ourselves unable to explain that judgment.

Since our ability to make moral judgments outpaces our ability to justify them, moral judgment does not seem to be the product of rational reflection. Might it be the product of an emotional system instead? Hauser grants that moral judgments are typically accompanied by emotions, but he suggests that these emotions are the result of the moral judgment rather than the cause. Part of his evidence for this claim comes from studies of patients with damage to the ventromedial prefrontal cortex. These patients appear to have reduced emotional responses to moral harms, yet their judgments appear to be identical to those of normal subjects when confronted with most moral dilemmas. Hauser nonetheless believes that emotions powerfully influence moral performance — by influencing our motivation to act morally — but that the moral faculty itself is independent of the emotional system. Moral competence is the product of an innate moral faculty whose optional parameters and exceptions are determined by the culture into which each of us is born.

There is little doubt that this book, written for a general audience, is the most important attempt to date to explain the psychological mechanisms of moral judgments. However, Hauser has made the unusual decision to publish it well before all the experimental data are in. For this reason, the book is sometimes frustratingly vague on key questions. Is the moral faculty cognitively penetrable — that is, can a person gradually alter its parameters through reflection — or is it more like the visual system, which remains subject to visual illusions even when we know full well that they are illusions? What accounts for the differences in moral judgments among people who grow up in the same culture, a difference that has no obvious parallel in the linguistic sphere? It would be churlish to criticize Hauser for the lack of clarity and detail on such matters. Moral Minds offers us the most important scientific contribution to moral psychology in many decades, and it is certain to inspire and inform debate across many fields for years to come.

Neil Levy, Ph.D.
University of Melbourne, 3010 Parkville, Australia
nllevy@unimelb.edu.au