Biological determinism, also known as genetic determinism, is the belief that human behaviour is directly controlled by an individual's genes or some component of their physiology, generally at the expense of the role of the environment, whether in embryonic development or in learning. Genetic reductionism is a similar concept, but it is distinct from genetic determinism in that the former refers to the level of understanding, while the latter refers to the supposedly causal role of genes. Biological determinism has been associated with movements in science and society including eugenics, scientific racism, and the debates around the heritability of IQ, the basis of sexual orientation, and sociobiology.
In 1892, the German evolutionary biologist August Weismann proposed in his germ plasm theory that heritable information is transmitted only via germ cells, which he thought contained determinants (genes). The English polymath Francis Galton, supposing that undesirable traits such as club foot and criminality were inherited, advocated eugenics, aiming to prevent supposedly defective people from breeding. American physician Samuel George Morton and the French physician Paul Broca attempted to relate the cranial capacity (internal skull volume) to skin colour, intending to show that white people were superior. Other workers such as the American psychologists H. H. Goddard and Robert Yerkes attempted to measure people's intelligence and to show that the resulting scores were heritable, again to demonstrate the supposed superiority of people with white skin.
Galton popularized the phrase nature and nurture, later often used to characterize the heated debate over whether genes or the environment determined human behavior. Scientists such as ecologists and behavioural geneticists now see it as obvious that both factors are essential, and that they are intertwined, especially through the mechanisms of epigenetics.
The American biologist E. O. Wilson founded the discipline of sociobiology, founded on observations of animals such as social insects, controversially suggesting that its explanations of social behaviour might apply to humans.
In 1892, the Austrian biologist August Weismann proposed that multicellular organisms consist of two separate types of cell: somatic cells, which carry out the body's ordinary functions, and germ cells, which transmit heritable information. He called the material that carried the information, now identified as DNA, the germ plasm, and individual components of it, now called genes, determinants which controlled the organism. Weismann argued that there is a one-way transfer of information from the germ cells to somatic cells, so that nothing acquired by the body during an organism's life can affect the germ plasm and the next generation. This effectively denied that Lamarckism (inheritance of acquired characteristics) was a possible mechanism of evolution. The modern equivalent of the theory, expressed at molecular rather than cellular level, is the central dogma of molecular biology.
Early ideas of biological determinism centred on the inheritance of undesirable traits, whether physical such as club foot or cleft palate, or psychological such as alcoholism, bipolar disorder and criminality. The belief that such traits were inherited led to the desire to solve the problem with the eugenics movement, led by a follower of Darwin, Francis Galton (1822–1911), by forcibly reducing breeding by supposedly defective people. By the 1920s, many U.S. states brought in laws permitting the compulsory sterilization of people considered genetically unfit, including inmates of prisons and psychiatric hospitals. This was followed by similar laws in Germany, and throughout the Western world, in the 1930s.
Under the influence of determinist beliefs, the American craniologist Samuel George Morton (1799–1851), and later the French anthropologist Paul Broca (1824–1880), attempted to measure the cranial capacities (internal skull volumes) of people of different skin colours, intending to show that whites were superior to the rest, with larger brains. All the supposed proofs from such studies were invalidated by methodological flaws. The results were used to justify slavery, and to oppose women's suffrage.
Heritability of IQ
Alfred Binet (1857–1911) designed tests specifically to measure performance, not innate ability. From the late 19th century, the American school, led by researchers such as H. H. Goddard (1866–1957), Lewis Terman (1877–1956), and Robert Yerkes (1876–1956), transformed these tests into tools for measuring inherited mental ability. They attempted to measure people's intelligence with IQ tests, to demonstrate that the resulting scores were heritable, and so to conclude that people with white skin were superior to the rest. It proved impossible to design culture-independent tests and to carry out testing in a fair way given that people came from different backgrounds, or were newly arrived immigrants, or were illiterate. The results were used to oppose immigration of people from southern and eastern Europe to America.
Human sexual orientation
Human sexual orientation, which ranges over a continuum from exclusive attraction to the opposite sex to exclusive attraction to the same sex, is caused by the interplay of genetic and environmental influences. There is considerably more evidence for biological causes of sexual orientation than social factors, especially for males.
Sociobiology emerged with E. O. Wilson’s 1975 book Sociobiology: The New Synthesis. The existence of a putative altruism gene has been debated; the evolutionary biologist W. D. Hamilton proposed "genes underlying altruism" in 1964, while the biologist Graham J. Thompson and colleagues identified the genes OXTR, CD38, COMT, DRD4, DRD5, IGF2, GABRB2 as candidates “affecting altruism”. The geneticist Steve Jones argues that altruistic behaviour like "loving our neighbour" is built into the human genome, with the proviso that neighbour means member of "our tribe", someone who shares many genes with the altruist, and that the behaviour can thus be explained by kin selection. Evolutionary biologists such as Jones have argued that genes that did not lead to selfish behaviour would die out compared to genes that did, because the selfish genes would favour themselves. However, the mathematician George Constable and colleagues have argued that altruism can be an evolutionarily stable strategy, making organisms better able to survive random catastrophes.
Nature versus nurture debate
The belief in biological determinism was matched in the 20th century by a blank slate denial of any possible influence of genes on human behavior, leading to a long and heated debate about "nature and nurture". By the 21st century, many scientists had come to feel that the dichotomy made no sense. They noted that genes are expressed within an environment, in particular that of prenatal development, and that gene expression is continuously influenced by the environment through mechanisms such as epigenetics. Epigenetics provides evidence that human behaviors or physiology can be decided by interactions between genes and environments. For example, monozygotic twins usually have exactly same genomes. Scientists have focused on comparison studies of such twins for evaluating the heritability of genes and the roles of epigenetics in divergences and similarities between monozygotic twins, and have found that epigenetics plays an important part in human behaviors, including the stress response.
- Behavioral epigenetics – Study of epigenetics' influencing behavior
- Behavioural genetics – Study of genetic-environment interactions influencing behaviour
- Dual inheritance theory – Theory of human behavior
- Genetic fallacy – Fallacy of irrelevance
- Nature–culture divide – Theoretical foundation of anthropology
- Social determinism – Theory of human behavior
- de Melo‐Martín, Inmaculada (2003). "When Is Biology Destiny? Biological Determinism and Social Responsibility". Philosophy of Science. 70 (5): 1184–1194. doi:10.1086/377399. JSTOR 10.1086/377399.
I will use here 'biology' and 'genetics' ... interchangeably ... because this is the way they are used in most of the literature I analyze here ... Critics accuse those who use biology to explain every possible human trait of presupposing the truth of biological or genetic determinism.
- "Biological determinism". Oxford Reference. 2021. Retrieved 26 September 2021.
The idea that an individual's personality or behaviour is caused by their particular genetic endowment, rather than by social or cultural factors—by nature rather than nurture.
- Hayes, Dr Nicky; Stratton, Peter (2017-09-01). A Student's Dictionary of Psychology and Neuroscience. Routledge. p. 138. ISBN 978-1351803199.
- Allen, Garland E. (1984). "The Roots of Biological Determinism: review of The Mismeasure of Man by Stephen Jay Gould". Journal of the History of Biology. 17 (1): 141–145. doi:10.1007/bf00397505. JSTOR 4330882. PMID 11611452. S2CID 29672121.
- Lewontin, Richard; Rose, Steven; Kamin, Leon (1984). Not in Our Genes: Biology, Ideology and Human Nature. Pantheon Books. pp. 131–163.
- May, Robert M. (1 April 1976). "Sociobiology: a new synthesis and an old quarrel". Nature. 260 (5550): 390–392. Bibcode:1976Natur.260..390M. doi:10.1038/260390a0. PMID 11643303. S2CID 4144395.
- Normile, Dennis (2016). "Nature From Nurture". Science. 351 (6276): 908–910. doi:10.1126/science.351.6276.908. PMID 26917750.
- Powledge, Tabitha M. (2011). "Behavioral Epigenetics: How Nurture Shapes Nature". BioScience. 61 (8): 588–592. doi:10.1525/bio.2011.61.8.4.
- Moore, David S. (2003). The Dependent Gene: The Fallacy of Nature Vs. Nurture. Henry Holt. ISBN 978-0805072808.
- Weismann, August (1892). Das Keimplasma: eine Theorie der Vererbung [The Germ Plasm: A Theory of Inheritance] (in German). Jena: Fischer.
- Huxley, Julian (1942). Evolution, the modern synthesis. Allen and Unwin. p. 17.
- Turner, J. Scott (2013). Henning, Brian G.; Scarfe, Adam Christian (eds.). Biology's Second Law: Homeostasis, Purpose, and Desire. Beyond Mechanism: Putting Life Back Into Biology. Rowman and Littlefield. p. 192. ISBN 978-0-7391-7436-4.
Where Weismann would say that it is impossible for changes acquired during an organism's lifetime to feed back onto transmissible traits in the germ line, the CDMB now added that it was impossible for information encoded in proteins to feed back and affect genetic information in any form whatsoever, which was essentially a molecular recasting of the Weismann barrier.
- Galton, Francis (1874). "On men of science, their nature and their nurture". Proceedings of the Royal Institution of Great Britain. 7: 227–236.
- Allen, Garland Edward (9 December 2015). "Biological determinism". Encyclopædia Britannica.
- Gould, Stephen Jay (1981). The Mismeasure of Man. W. W. Norton.
- Frankowski, B. L.; American Academy of Pediatrics Committee on Adolescence (June 2004). "Sexual orientation and adolescents". Pediatrics. 113 (6): 1827–1832. doi:10.1542/peds.113.6.1827. PMID 15173519.
- Stuart, Gail Wiscarz (2014). Principles and Practice of Psychiatric Nursing. Elsevier. p. 502. ISBN 978-0-323-29412-6.
- Bailey, J. M.; Vasey, P. L.; Diamond, L. M.; Breedlove, S. M.; Vilain, E.; Epprecht, M. (2016). "Sexual Orientation, Controversy, and Science". Psychological Science in the Public Interest. 17 (21): 45–101. doi:10.1177/1529100616637616. PMID 27113562.
- LeVay, Simon (2017). Gay, Straight, and the Reason Why: The Science of Sexual Orientation. Oxford University Press. ISBN 978-0199752966.
- Balthazart, Jacques (2012). The Biology of Homosexuality. Oxford University Press. ISBN 978-0199838820.
- Hamilton, W. D. (1964). "The genetical evolution of social behaviour. I". Journal of Theoretical Biology. 7 (1): 1–16. Bibcode:1964JThBi...7....1H. doi:10.1016/0022-5193(64)90038-4. PMID 5875341.
- Hamilton, W. D. (1964). "The genetical evolution of social behaviour. II". Journal of Theoretical Biology. 7 (1): 17–52. Bibcode:1964JThBi...7...17H. doi:10.1016/0022-5193(64)90039-6. PMID 5875340.
- Thompson, G. J.; Hurd, P. L.; Crespi, B. J. (2013). "Genes underlying altruism". Biol Lett. 9 (6): 20130395. doi:10.1098/rsbl.2013.0395. PMC 3871336. PMID 24132092.
- Giberson, Karl (15 August 2014). "Book review: 'The Serpent's Promise', on Bible-Science tensions, by Steve Jones". The Washington Post. Retrieved 9 June 2018.
- Johnston, Ian (21 July 2016). "Altruism has more of an evolutionary advantage than selfishness, mathematicians say". The Independent.
- Constable, George W. A.; Rogers, Tim; McKane, Alan J.; Tarnita, Corina E. (2016-07-22). "Demographic noise can reverse the direction of deterministic selection". Proceedings of the National Academy of Sciences. 113 (32): E4745–E4754. arXiv:1608.03471. doi:10.1073/pnas.1603693113. PMC 4987790. PMID 27450085.
- Ridley, Matt (2003). Nature via Nurture: Genes, Experience, & What Makes Us Human. HarperCollins. ISBN 978-0-002-00663-7.
- Moore, David S. (2015). The Developing Genome: An Introduction to Behavioral Epigenetics (1st ed.). Oxford University Press. ISBN 978-0-199-92234-5.
- Gutiérrez, Luci (January 24, 2014). "Time to Retire The Simplicity of Nature vs. Nurture". Wall Street Journal.
- Berger, Shelley L.; Kouzarides, Tony; Shiekhattar, Ramin; Shilatifard, Ali (2009-04-01). "An operational definition of epigenetics". Genes & Development. 23 (7): 781–783. doi:10.1101/gad.1787609. ISSN 0890-9369. PMC 3959995. PMID 19339683.
- Petronis, Arturas (2006-07-01). "Epigenetics and twins: three variations on the theme". Trends in Genetics. 22 (7): 347–350. doi:10.1016/j.tig.2006.04.010. ISSN 0168-9525. PMID 16697072.
- Bell, Jordana T.; Spector, Tim D. (2011-03-01). "A twin approach to unraveling epigenetics". Trends in Genetics. 27 (3): 116–125. doi:10.1016/j.tig.2010.12.005. ISSN 0168-9525. PMC 3063335. PMID 21257220.
- Darnaudéry, Muriel; Maccari, Stefania (2008-03-14). "Epigenetic programming of the stress response in male and female rats by prenatal restraint stress". Brain Research Reviews. The endocrine nervous system: source and target for neuroactive steroids. 57 (2): 571–585. doi:10.1016/j.brainresrev.2007.11.004. ISSN 0165-0173. PMID 18164765. S2CID 28319093.