Blackwell Publishing, 2006. £50 (hardcover), £14.99 (paperback), ix + 280 pp. ISBN 1-4051-1062-7 (hardcover)/1-4051-1061-9 (paperback)
What can you expect in this day an age, when reaching to the bookshelf for the latest offering on the Nature–Nurture debate? Will it be a diatribe against genes and inherited aspects of behaviors? Will we be told we are all born equal, a blank slate, and then emerge to become the different people we are through our different experiences? Or will we be told that genes are in charge and that somehow we are an elaborate genetically programmed automaton?
It is in the center of this battlefield where Michael Rutter chooses to start his tour, with the provocative question ‘Why is the topic of genes and behavior controversial?’ Within the first few pages, where he outlines the structure of the book, we are introduced to Mendel, Haldane, Pearson and Fisher, the genome project and shortly thereafter confronted with the wonderfully blunt headings ‘The supposed poor quality of the evidence from twin and adoptee studies’, ‘Fraud and bias in behavioral genetics’ not to mention the acute and delightful ‘Acceptance of funding from organizations with an axe to grind’. This is fast moving stuff.
By this point, you realize you are having the privilege of striding through the landscape of behavioral genetics, escorted by a scientist who has been in the thick of it for his long and distinguished career. Where there is a spade, it will be called a spade and where there is a sow's ear, you will not be told it is a silk purse. It is the directness and the rich array of examples and anecdotes that make this book such fun.
As a reader of this learned journal you will most likely be an academic in the behavioral sciences, and the more senior you are, the tougher you will be to please. Why after all should you get a book on a subject you know everything about? From this reviewer's molecular biological perspective, I found much to learn. Early on, we are treated to descriptions of human genetic study designs, which were clear and concise and enlivened by a rich array of relevant findings. Unraveling the detailed design of twin studies was followed by the findings of these approaches in a catalogue of mental illness after which Rutter concludes that ‘virtually all psychiatric disorders show a significant genetic contribution to individual differences, with heritabilities at least in the 20 to 50 percent range’.
So where does the 50 to 80 on the other side of the equation come from? Rutter turns his attention to this issue by first explaining the strategies for examining environmentally mediated risks. Here we learn of twin adoption studies of children abused and neglected, longitudinal studies of institutional deprivation with its resulting psychological dysfunction and the impact on poverty and childhood-disruptive behavior of a new casino on an Indian reservation, as well as the effects of cannabis. I found this chapter fascinating and would have liked to read much more and was left agreeing with Rutter's conclusion that ‘It is all too obvious that much remains to be learned about the effects of experiences on the organism, and that remains a key need for the future’.
After a brief, and for some readers perhaps an essential description of the basics of DNA, we move onto association studies and finding susceptibility genes in mental illness. Following on are chapters on ‘Gene-environment interplay’ and ‘What environments do to genes’. Much territory is covered ranging from genetic testing of susceptible individuals to how environment can lead to activation of biochemical pathways.
The concluding chapters bring the tour into sharp focus by addressing seven major points. This is well worth reading and rereading, as these conclusions will interest a wide audience. I was particularly interested in conclusion number three, which states that ‘there is no clear-cut qualitative distinction between normal psychological variations and clinically significant mental disorders’. You will have to read the book to find out more.
This is not a book where you will learn the latest in cellular neurophysiology or molecular biology of nerve cells. It is also sharply human, with little to say about animal studies. These points are not shortcomings, but simply emphasize that this is a book about human nature and nurture. The explanations of human genetic study designs were very well presented, not weighed down with statistical equations and continually linked to real examples of biological interest. The core of this book is to present a personal view of the advances of the 20th century from a scholar of human behavioral genetics. It is this core that can be seen as a foundation for those future studies aimed at understanding, presumably in great mechanistic detail, how environment shapes us in the context of our inherited genetic differences. A careful reading of this book by a young scientist should inspire them to tackle these most important issues.