The use of inheritance, and then later the use of genetics, to argue for determinism, has waxed and waned over the history of biology. Reviewing some of this background is important for understanding where we are today.
Some Historical Background
Overall it was the philosophers of earlier centuries who established powerful arguments in support of human freedom, and it was then the biologists from the late nineteenth century onwards who began to seriously undermine those convictions. The philosophers on the side of freedom included John Locke (1632-1704), Immanuel Kant (1724-1804) and John Stuart Mill (1806-1873).
Charles Darwin (1809-1882) was no determinist, but neither did he support the more radical concept of human freedom presented by the likes of Stuart Mill, arguing that ‘social feelings’ were inherited. But it was really in the writings of Darwin’s cousin, John Galton (1822-1911), that the modern era of biological determinism was born. It was Galton who popularized the famousIn the public consciousness, genetics was tied to eugenics which was linked in turn to the holocaust, so that any suggestion of the inheritance of human behaviors became treated with deep suspicion. ‘nature-nurture’ dichotomy, emphasizing in his book English Men of Science: Their Nature and Nurture that “no carefulness of nurture can overcome the evil tendencies of an intrinsically bad physique, weak brain, or brutal disposition.”F. Galton, English Men of Science: Their Nature and Nurture (London: Macmillan, 1874).. For Galton nurture was important, but nature always came out on top. It was Galton who invented the word ‘eugenics,’ a relatively benign concept in his own day, but one that later became so loaded with dread during the history of Nazi Germany.
The Mendelian laws of inheritance, originally published in German in 1866, were rediscovered around 1900, and the word ‘gene’ was invented by the Danish botanist Wilhelm L. Johannsen in 1909. Eugenics became both popular and respectable during the early decades of the twentieth century. “More children from the fit, less from the unfit, that is the chief issue of birth control,” declared the feminist campaigner Margaret Sanger in 1919.D. B. Paul, Controlling Human Heredity: 1865 to the Present (Amherst, N.Y.: Humanity Books, 1995). Every member of the first editorial board of the American journal Genetics, founded in 1916, supported the eugenics movement.K. M. Ludmerer, Genetics and American Society: A Historical Appraisal (Baltimore, MD: Johns Hopkins University Press, 1972).
The number of characteristics which eugenicists believed could be transmitted genetically was particularly all-embracing. They included not only such defects as insanity, mental deficiency and epilepsy, but also unemployment, alcoholism, pauperism and criminality.J. Woodhouse, “Eugenics and the Feeble-Minded: The Parliamentary Debates of 1912-14,” History of education, 11 (1982): 127-137.
Eugenics was taught at most major American universities, or became a standard part of genetics courses, and was endorsed in more than 90 percent of US high school textbooks.S. Selden, “The Use of Biology to Legitimate Inequality: The Eugenics Movement within the High School Biology Textbook, 1914-1949,” in W. Secada (ed.), Equity in Education (New York, NY: Falmer Press, 1989).
Two major factors helped to counteract the strong genetic determinism that characterized the earlier decades of the twentieth century, the first academic and the second political. The academic swing of the pendulum arose from the behavioral psychology that came to dominate the field of psychology from the 1930’s onwards, associated in particular with the works of J. B. Watson and B. F. Skinner. Genetic determinism was replaced by environmental determinism. The major political factor was the huge reaction against the horrors of the holocaust in Germany once these became known in the years following the Second World War. In the public consciousness, genetics was tied to eugenics which was linked in turn to the holocaust, so that any suggestion of the inheritance of human behaviors became treated with deep suspicion.
Genetics and Determinism Today
Today all professional geneticists are highly sensitized to the earlier racist and eugenic misapplications of their profession. But their language can sometimes imply genetic determinism and certainly their results are often presented in the media as if this were the case. Here we will summarize four particular fields in which such impressions can arise.
Biologists love adding ‘omic’ on to the end of words to turn the word into a whole field of enquiry and ‘genomics’ is no exception. The word ‘genome’ simply refers to the sum total of the information containedThe publication of the full human genome DNA sequence in 2004 provided much opportunity for dramatic descriptions, some of which lent themselves in media reports to somewhat deterministic implications. in the DNA of any particular organism, so ‘genomic’ then refers to the study of its genome.
The publication of the full human genome DNA sequence in 2004 provided much opportunity for dramatic descriptions, some of which lent themselves in media reports to somewhat deterministic implications, though it should be emphasized that the language used by Dr. Francis Collins, Director of the Human Genome project at the time, was very careful. But metaphors for the genome such as ‘the Holy Grail,’ ‘the Book of Life,’ and ‘the Code of Codes’ were all used by those working in the biological sciences. The ‘blueprint’ metaphor became very popular, replacing older, less deterministic terminology such as ‘genetic lottery.’C. M. Condit, M. Gronnvoll, J. Landau, et al. “Believing in Both Genetic Determinism and Behavioral Action: A Materialist Framework and Implications,” Public Underst. Sci., 18 (2009): 730-746. Walter Gilbert, who first used the phrase ‘Holy Grail’ to describe the genome at a conference at Los Alamos in 1986, and who was one of the foremost promoters of the Human Genome Project, described its potential with this graphic image:
One will be able to pull a CD out of one’s pocket and say, “Here is a human being; it’s me!” . . . To recognize that we are determined, in a certain sense, by a finite collection of information that is knowable will change our view of ourselves.W. Gilbert, “A Vision of the Grail,” in D. Kevles, (ed.) The Code of Codes: Scientific and Social Issues in the Human Genome Project (Cambridge, MA: Harvard University Press, 1992).
Some have tried to use genomic data with specifically deterministic and racist goals in mind. In 2014, A Troublesome Inheritance—Genes, Race and Human History by Nicholas Wade stirred up a hornets’ nest with its suggestion that genetic differences between ‘the three major races’ help to explain economic differences between races and “the rise of the West.” Hundreds of geneticists published their opposition to such views in the media, but this and other examples show how important it is to avoid inappropriate metaphors such as ‘blueprint’ in the presentation of human genomic data.
The huge field of medical genetics can readily lend itself to ideas of genetic determinism for the simple reason that many single gene disorders do indeed have clearly predictable medical outcomes. The situation is very different in psychiatric genetics in which hundreds or possibly thousands of variant genes contribute to syndromes such as Schizophrenia, Bipolar Disorder, Major Depression, and Autism. So the role of variant genes in such syndromes is probabilistic rather than deterministic. But certainly single-gene disorders illustrate a form of medical determinism, though this is clearly distinct from the broader discussion about determinism amongst those who suffer no such pathologies.
The proliferation of direct-to-consumer (DTC) genetic testing companies has also contributed to the idea that it is the genes that are pulling the strings of human destiny. One in 25 Americans now receive personalized genetic test reports that predict their probabilities of developing various medical conditions over their coming lifetime.A. Regalado, “2017 was the year consumer DNA testing blew up,” MIT Technology Review https://www.technologyreview.com/s/610233/2017-was-the-yearconsumer-dna-testing-blew-up/ In 2017 alone, more people had genetic tests carried out than in all the previous years combined. One might fondly imagine that when people are told that they have an increased probability of developing a certain disease, based on their genes, that they will then take extra precautions, such as better diet and increased exercise, to avoid such an outcome. But surveys show that the opposite tends to be the case—once people learn that their chance of a disease, or a trait like obesity, is (supposedly) more based on genes than on the environment, then they become more fatalistic.I. Dar-Nimrod, B. Y. Cheung, M. B. Ruby, et al. “Can Merely Learning About Obesity Genes Affect Eating Behavior?” Appetite, 81 (2014): 269-276. See also S. Persky, S. Bouhlal, M. R. Goldring, et al. “Beliefs about Genetic Influences on Eating Behaviors: Characteristics and Associations with Weight Management Confidence,” Eat Behav, 26 (2017): 93-98.
Even more striking is the finding from a psychology research group at Stanford University that telling people that they are more likely to develop a medical condition due to their genetic constitution causes people to display precisely the kind of risk factors for that condition.B. P. Turnwald, J. P. Goyer, D. Z. Boles, et al. ‘Learning One’s Genetic Risk Changes Physiology Independent of Actual Genetic Risk,” Nat Hum Behav, 3 (2019): 48-56. For example, merely receiving genetic risk information was enough to increase the heart-rate, change how running perseverance was perceived during exercise and change how fullness was perceived after eating. So the genetic information changed the mindset of the people being studied in such a way that it increased the risk of developing precisely the syndromes for which they had been told they had a greater genetic risk. In fact, in some cases the risk from being told was greater than the actual genetically predicted risk, so presumably in such cases it would be better not to tell people that they had an increased genetic risk at all! We humans are highly suggestible.
The specter of prenatal embryo genetic testing is providing further fuel for genetically deterministic narratives. The front page of the UK Guardian newspaper in 2019 proclaimed that “IVF couples could be able to choose the smartest embryo—US scientist says it will be possible to rank embryos by ‘potential IQ’ within ten years.”H. Devlin, The Guardian, 24th May 2019, p.1. This was based on comments by Stephen Hsu, senior vice-president for research at Michigan State University, but who is also co-founder of a company called ‘Genomic Prediction’ which, no surprise here, might well be offering such a service over the coming years. The claim made in the Guardian headline is highly dubious, but for the moment we simply note the deterministic framework within which the claims are being made.
Probably the genetic sub-field that displays the most deterministic overtones is behavioral genetics. One of the reasons for this is the technical and often misunderstood use of the word ‘heritability.’ The word has two distinct meanings. The first meaning simply refers to inheritance. But the second meaning is more technical and refers to “the proportion of variance of a trait in a particular population that can be ascribed to genetic variation in that population” which is Once people learn that their chance of a disease, or a trait like obesity, is (supposedly) more based on genes than on the environment, then they become more fatalistic.quite different. A scientific report may say that intelligence, for example, has a heritability of 50 percent, meaning that 50 percent of the variance of this trait (however measured) in a population can be attributed to genetic variance, but what people understand from the news report is that 50 percent of their own personal intelligence is inherited from their parents, which is not at all the claim that is being made.
Unfortunately some workers in the field also use language that has deterministic overtones. For example, leading behavioral geneticist Robert Plomin from London’s Institute of Psychiatry (where I did my PhD, incidentally) faced a minor storm with his book Blueprint published in 2019, writing that “DNA is the major systemic force, the blueprint, that makes us who we are. The implications for our lives – for parenting, education and society – are enormous.”R. Plomin, Blueprint, Allen Lane, 2018. The impression that our genes determine our social endowment is given further reinforcement by comments such as “Nice parents have nice children because they are all nice genetically” and “DNA isn’t all that matters but it matters more than everything else put together.” All this led a reviewer of Blueprint in the journal Nature to claim that “It’s never a good time for another bout of genetic determinism, but it’s hard to imagine a worse one than this.”N. Comfort, “Genetic Determinism Redux,” Nature 561 (2018): 461-463. Strong words indeed, but an indication of how passions run deep in this particular field.
Today’s geneticists are, on the whole, very concerned to demonstrate that their data provide no support for determinism. Their stance on this point is correct. However, at the same time, there is a minority of workers in the field, as noted, who exaggerate their results or are careless with their language in such a way that determinism is implied. Genetic testing and the media handling of genetic discoveries can also support genetic determinism by implication, if not directly. Genetic determinism is often absorbed by a process of cultural osmosis rather than by the overt claims of geneticists.