The Ethical Brain

In The Ethical Brain, Dartmouth cognitive neuroscientist Michael S. Gazzaniga explores the evidence for hardwired brain functions that contribute to a universal set of human ethical values. Gazzaniga, a member of the President’s Council on Bioethics, has had plenty of experience grappling with issues ranging from when a fetus should be accorded the status of a person to whether parents should in the future be allowed to genetically select intelligent children, and he discusses those topics and others from a neuroscientist’s perspective in this brief book.

The book begins with fairly routine discussions of what neuroscience contributes to the familiar debates on the moral status of embryos and on end-of-life issues. Psychiatrists will find Gazzaniga’s chapters on “Better Brains Through Genes” and “Shaping the Smart Brain With Drugs” more thought-provoking in their discussions of the heritability of intelligence and its potential chemical enhancement. He foresees a day when gene therapy allows more people to be really smart. More problematic is Gazzaniga’s assertion that cognitive enhancement therapy and drugs are inevitable and his belief that government should avoid regulating them. In libertarian fashion, Gazzaniga is sanguine that people’s ethical and moral senses will prevent societal dislocation from a flood of newly smart people.

In later chapters, Gazzaniga writes that brain function research is likely to identify with increasing certainty what areas of the cerebral cortex are most involved in moral reasoning and eventually elucidate a cortical basis for such ethical principles as the wrongfulness of killing. He makes clear, however, that he believes there is a limit to what brain research can contribute to an appreciation of individual moral responsibilities, since people’s responsibilities toward each other by definition exist in a social context, rather than in isolated brains.

Gazzaniga concludes his book with a discussion of how human empathy originates. He thinks it is likely that “mirror neurons” give a person the ability to put himself in another’s place and to figure out what the other person would want in a given situation. Gazzaniga sees this neurologically grounded empathy as the basis for certain universal ethical principles. He believes that an understanding of those ethical principles all people carry inside will help people of different religions and belief systems to get along, even when they do not agree about individual ethical issues.

In The Ethical Brain, we thus find echoes of earlier thinking in the field of sociobiology in which attributes such as altruism, tool use, and intentional warfare were tied to an explicit biological origin. It is interesting that these attributes, which were previously thought to separate our species from all others, are also no longer identified as unique to humankind. Just as the observations and implications of sociobiology were criticized by diverse members in our society for widely varying theoretical, philosophical, and religious concerns, we anticipate that the ideas laid forth by Gazzaniga will also be met with a mixed response. Nevertheless, it addresses a field of importance to psychiatry, the neurosciences, bioethics, and our society; it should evoke and provoke more sophisticated thinking in an as yet relatively unexplored domain.

The Ethical Brain is generally clearly written, and it includes a wealth of references that guide the reader to helpful texts in neuroscience and sociobiology for further exploration.