BOOK REVIEW
HARDWIRED BEHAVIOR: WHAT NEUROSCIENCE REVEALS ABOUT MORALITY
By Laurence Tancredi
Cambridge University Press, 2005
Hardback $19.13

Laurence Tancredi is uniquely qualified to write about the neural roots of human morality. As a lawyer, Tancredi has consulted in many legal cases involving the effects of toxins on brain function and behavior, as well as criminal cases involving assault, rape, and homicide. In addition, he is a noted physician and Professor of Psychiatry at New York University School of Medicine, as well as the author of several books on law, ethics, and psychiatry.

In this new book, Tancredi poses such questions as: Are the brain and the mind separate? How does the physical brain work to develop moral decisions? What is the biology of mental illness? Are specific moral rules innate? What is the impact of hormones on psychosexual development? How important is free will? The answers to these questions, as Tancredi shows, are rapidly emerging as our understanding of the brain evolves- and those answers are challenging our most basic ideas about good, evil, and free will.

Hardwired Behavior is written to be easily understood by lay readers, but will also be of great interest to behavioral researchers and legal professionals. Each chapter of the book has between 19 and 75 references, providing additional resources.

We strongly recommend this book for anyone involved in the study of immoral behavior in such disparate areas as money, deception, sex, or criminal activity.

Our view of morality has already been altered by new understanding of brain biology, and at the rate that new discoveries are being made, that view will change even more in the future. With these changes will come the understanding that we can intervene at the most fundamental biological levels to affect moral development.

(R)ecent neuroimaging and genetic studies have revealed specific brain images that correlate with discrete gene dysfunction to produce a child who is very likely to become highly violent and antisocial as an adult.

Since the late 1980s, positron emission tomography (PET) studies have been conducted on violent and aggressive offenders. These have shown correlations between brain metabolism and the potential for violent behavior. PET studies of repetitively violent offenders revealed decreased cortical blood flow and hypometabolism in their nondominant frontal and temporal lobes, compared to control subjects. Some even showed involvement into the prefrontal region, which affects cognitive understanding.

(H)ow many of us would accept the idea that our personal choices in life are influenced, even determined, by brain biology? We resist this notion even if we've known older people, perhaps in our own families, who have suffered stroke or a serious disease such as Alzheimer's, and we've seen how such physical brain injuries can affect not only their ability to move but their ability to think rationally.

(N)euroscience is forcing us to rethink the extent of our personal control over our choices, and the implications of limits on personal control over our choices are nothing short of mind-boggling.

Imaging studies of true psychopaths, who lack empathic abilities, are demonstrating structural and functional abnormalities in some of these key areas of the brain, particularly the prefrontal cortex and the limbic system.

(E)ach of us holds our own position on the spectrum of being influenced by neurochemicals and brain changes from the prenatal phase of our development. We may not be able to control gender or sexual preferences, as these appear to be shaped prenatally and during the early years of development, but most of us can exert some control over our behavior. Nonetheless, the degree of that control is largely determined by biological forces.

Understanding how parts of the brain work to affect our thinking and behavior may eventually transform our formerly sacrosanct beliefs about personal identity and free will.

Our objective should be to use neuroscientific information-including diagnostic measures such as imaging technologies-to address rationally the responsibility of those who commit "bad" or criminal acts.