Some of us, most of us, take what science tells us very seriously. Our view of ourselves, and of others, is heavily informed by what we believe is the scientific position. If it turns out that we are little more than our genes, that we are biochemical robots, then we must face up to the truth, dispiriting as it may be, and deal with it as best we can. We must not shirk. The philosopher J.R. Lucas said: `Modern man is inclined to be a metaphysical masochist, drawn to any world-view that denies his humanity by cutting him down to merely animal or thingly size.' In the face of genetic determinism, we are many of us masochists, and nearly all of us half-believers. Our `thingly size' is the size of a gene.
Is this masochism really necessary? Is this view of ourselves really demanded by current science? Concentrating on the field of psychiatric genetics, Jay Joseph argues that the genetic determinism so taken for granted in modern times is not based on sound science. This is a serious and controversial claim. Many people become angry if you even so much as suggest that a psychiatric disorder may not be genetic. Strong arguments are therefore needed. With the knowledge that he is militating against a well-entrenched orthodoxy, Joseph has written this extremely detailed, rigorously argued book, dedicating many of its chapters to lengthy critical assessments of original research papers. While some may be put off by the rather pedantic level of argumentation, it is, to my mind, absolutely necessary; and if you are willing to put the time in, occasionally exhilarating. It is too easy for genetically oriented researchers to blithely dismiss serious criticism as the work of know-nothing `armchair critics' with ideological agendas. Joseph is no armchair critic. Although he is a clinical psychologist and not a research scientist, his doctoral thesis was a critical examination of the schizophrenia twin studies literature, and the majority of his publications since then have been dedicated to this very specific, and very important, area. As the book makes clear, he is often more familiar with the foundational research of psychiatric genetics than the researchers themselves.
Joseph's scholarship is outstanding; his level of familiarity with the science and history of psychiatric genetics is immense. Primary and secondary sources are quoted often and at length, everything is thoroughly sourced, the arguments proceed clearly and logically, and his tone is measured, professional. In cases of obvious academic fraud and gross incompetence, Joseph is careful not to ascribe conscious intent, opining more generally at the `unfortunate' state of affairs. Only once does he explicitly get angry with a few modern psychiatric geneticists, and it's to call them `poor historians indeed' in a footnote. Seeing as it was in the context of their attempted absolution of the leaders of the Munich School (an early psychiatric genetic organisation) from complicity in the Nazi eugenic and extermination programs, when widely available documentary evidence suggests very strongly otherwise, one can understand Joseph's academic `outburst'. That the founder of the school is claimed by a certain psychiatric geneticist to have been disgusted by Hitler's misuse of his research, even though it is widely known that he was not only a fervent support of the Nazi government but a formal legislator of some of its most draconian eugenics policies, is enough to make one pause and consider the lengths that people will go to defend their world-view, and just how many readers they are willing to lead astray.
Although the historical analyses in this book are fascinating, and even disturbing, the large majority of its contents are devoted to scientific analysis. This is where Joseph is at his most brilliant. His critique of the Equal Environment Assumption in all its varied and bizarre reformulations is a supreme example of logical analysis. Here Joseph cuts to the quick of psychiatric genetics, because if the EEA is invalid, as Joseph cogently argues, then the vast majority of twin studies done to date are scientifically useless. When one considers their many other, more particular, invalidating flaws (biased statistical manipulation, the post hoc redefinitions of the disorder under study to achieve statistical significance, among many others) the case for the genetic transmission of psychiatric disorders is about as scientifically compelling as phrenology.
There is much more to this book than a one thousand word review can do justice to. By the book's conclusion, I was convinced that the well-publicised claims about the genetic determination of psychiatric disorders are based more on politics, rhetoric and second-hand information than sound science. It took a book of this level of complexity and detail to convince me. Vague humanistic platitudes, while comforting for a time, are hard to sustain against a countervailing science. It is liberating to know that, in the case of psychiatric and behavioural genetics, the `countervailing science' is largely built on air, and that the evidence, in fact, supports a more open view, where human beings are genuine individuals, not shambling automata, whose psychological difficulties are not the fault of their broken genes, but caused by well-known, and repairable, psychological and environmental factors. I will end this review as I began it: with a quotation from J.R. Lucas, former president of the British Society for the Philosophy of Science. His writings on human identity and value are among the best I've ever read, and show that to be scientific does not imply belief in the brutal pessimism of reductionist science, of which psychiatric and behavioural genetics are complementary parts. I am confident that Joseph would agree with the following passage.
`Each [of us] is a definite individual, ultimately responsible for what he decides to do, while being also an indeterminate shimmering of different personalities, revealed and developed in different personal relationships. Each is unique, of infinite complexity, transcending all stereotypes and neat classification, while needing also to be a safe pair of hands, who can be relied on to do his bit when required.'