Tag: Genetics

The wealthy, and the institutions they finance and promote, look favorably upon research whose authors claim that economic disparities are rooted in biology, and are not harmful to humanity as a whole. But there are countless obvious real-world examples showing that political policies, social struggles, and public health programs, including those involving the adjustment of income differences, lead to improved health and well-being.

Richard Bentall and David Pilgrim offer their critique of genetic theories of schizophrenia for the Conversation. "The high heritability estimates reported in earlier quantitative...

A dilemma for all of us who are struggling to broaden our understanding of human distress beyond simplistic, pessimistic, bio-genetic ideology, and to improve our mental health services accordingly, is whether or not to soften our criticisms of psychiatry in the hope of reaching those psychiatrists whose minds are not totally closed. But doing so rests on the assumption that change can come from within the profession. For the last few decades examples of that are few and far between.

The March 3^rd, 2016 edition of the Wall Street Journal featured an article by past President of the American Psychiatric Association (APA) Jeffrey Lieberman and his colleague, computational neuroscientist Ogi Ogas. The article was entitled “Genetics and Mental Illness—Let’s Not Get Carried Away.” In their piece, the authors started by expressing the belief that a recent study identified a gene that causes schizophrenia, and then discussed whether it is desirable or possible to remove allegedly pathological genes in the interest of creating a future “mentally perfect society.” The authors of the article, like many previous textbook authors, seem unfamiliar with the questionable “evidence” put forward by psychiatry as proof that its disorders are “highly heritable” In fact, DSM-5 Task Force Chair David Kupfer admitted that “we’re still waiting” for the discovery of “biological and genetic markers” for psychiatric disorders.

Although it is axiomatic in psychiatry that genetic factors are involved in bipolar disorder (manic-depression), and that they play a predominant role, there currently exists little if any scientifically acceptable evidence that bipolar disorder and other “affective disorders” are caused by disordered genes. Given almost 50 years of gene discovery claims that were not confirmed by replication attempts, we must assume by default that current gene finding claims are false-positive results as well. In the 1920s, pioneering psychiatric geneticist Ernst Rüdin decided against publishing his large family study of “manic-depressive insanity,” most likely because the results did not fit his theories of Mendelian inheritance, and failed to support his advocacy of eugenic policies.

Human behavioral genetics and its allied field of psychiatric genetics are in trouble, as unfulfilled gene discovery expectations during the “euphoria of the 1980s” have continued to the present day, leading to researchers’ “nonreplication curse” dysphoria of the 2010s. In my recent book The Trouble with Twin Studies: A Reassessment of Twin Research in the Social and Behavioral Sciences, I presented a detailed argument that genetic interpretations of the common “classical twin method” finding that reared-together MZ twin pairs resemble each other more (correlate higher) for behavioral characteristics than do reared-together same-sex DZ twin pairs are invalid because, among other reasons, the twin method’s crucial MZ-DZ “equal environment assumption” (EEA) is false.

In a 2013 edition of the Journal of the History of Biology, Norbert Wetzel and I published an article on the Swiss-German psychiatric geneticist Ernst Rüdin (1874-1952) and his close colleagues, and how their work and crimes in the Nazi era have been discussed or ignored by contemporary psychiatric genetic writers and researchers. Here I would like to summarize the main points we raised in that article, and to make several additional observations. Whether Rüdin reluctantly aided and helped implement the “euthanasia” killing program in support of the war effort, or more likely, that he saw it as the crowning achievement of his decades of psychiatric genetic research based on racial hygienic (eugenic) principles, is an issue that may be decided in the future.

A key psychiatric genetic concept is heritability. The concept was originally developed as a tool to help predict the results of selective breeding programs of farm animals,1 but has been extended in the past few decades as an indicator of the strength or magnitude of genetic influences on various psychiatric disorders and behavioral characteristics. Numerical heritability estimates have been a mainstay of the field of behavioral genetics, but here I would like to focus on problems with the heritability concept in psychiatry, while keeping in mind that most of the points made here and by previous critics apply to the use of heritability estimates in all areas of human behavior.

In the May 20th, 2015 edition of the Huffington Post, Macrina Cooper-White reported on a recently published meta-analysis (analysis of combined studies) of 2,748 twin studies performed in 39 different countries published between 1958 and 2012, which looked at more than 17,000 physical, medical, and psychological characteristics (traits). Cooper-White concluded that the results of this study indicate that the nature-nurture debate “may now be over.”

There seems to be no end to illogical and even comical “findings” from MZ-DZ twin method comparisons, where the original twin researchers argue that the greater behavioral resemblance of reared-together MZ (monozygotic, identical) versus same-sex DZ (dizygotic, fraternal) twin pairs demonstrates the “heritability” of the behavioral characteristic in question. Among these we find a twin study whose authors concluded in favor of a genetic basis for being a “born again Christian” (65% heritability), another that found important genetic influences on tea and coffee drinking preferences, and still another that found that the heritability of “loneliness in adults” is 48%.