Biological determinism

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Biological determinism, also known as genetic determinism,[1] 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.[2] 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.[3] Biological determinism has been associated with movements in science and society including eugenics, scientific racism, and the debates around the heritability of IQ,[4] the basis of sexual orientation,[5] and sociobiology.[6]

In 1892, the German evolutionary biologist

measure people's intelligence and to show that the resulting scores were heritable, again to demonstrate the supposed superiority of people with white skin.[4]

Galton popularized the phrase

social insects, controversially suggested that its explanations of social behaviour might apply to humans.[6]

History

in each generation from the germ plasm.

Germ plasm

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.[9] 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.[10] The modern equivalent of the theory, expressed at molecular rather than cellular level, is the central dogma of molecular biology.[11]

Eugenics

nature and nurture.[12]

Early ideas of biological determinism centred on the inheritance of undesirable traits, whether physical such as

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.[13][4][14]

Scientific racism

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.[4]

Heritability of IQ

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.[4]

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,[15] is caused by the interplay of genetic and environmental influences.[16] There is considerably more evidence for biological causes of sexual orientation than social factors, especially for males.[15][17][18][19]

Sociobiology

E. O. Wilson reignited debate on biological determinism with his 1975 book Sociobiology: The New Synthesis.

IGF2, GABRB2 as candidates "affecting altruism".[22] 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.[23] 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.[24][25]

Nature versus nurture debate

The belief in biological determinism was matched in the 20th century by a

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.[26][27][28] Epigenetics provides evidence that human behaviours or physiology can be decided by interactions between genes and environments.[29] For example, monozygotic twins usually have exactly identical 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 behaviours, including the stress response.[30][31][32]

See also

References

  1. S2CID 224834276
    . 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.
  2. ^ "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.
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  5. ^ Lewontin, Richard; Rose, Steven; Kamin, Leon (1984). Not in Our Genes: Biology, Ideology and Human Nature. Pantheon Books. pp. 131–163.
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  9. ^ Weismann, August (1892). Das Keimplasma: eine Theorie der Vererbung [The Germ Plasm: A Theory of Inheritance] (in German). Jena: S. Fischer Verlag.
  10. ^ Huxley, Julian (1942). Evolution, the modern synthesis. Allen and Unwin. p. 17.
  11. 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. {{cite book}}: |work= ignored (help
    )
  12. Proceedings of the Royal Institution of Great Britain
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  13. ^ Allen, Garland Edward (9 December 2015). "Biological determinism". Encyclopædia Britannica.
  14. ^ Gould, Stephen Jay (1981). The Mismeasure of Man. W. W. Norton.
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  23. ^ 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.
  24. ^ Johnston, Ian (21 July 2016). "Altruism has more of an evolutionary advantage than selfishness, mathematicians say". The Independent.
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  28. ^ Gutiérrez, Luci (January 24, 2014). "Time to Retire The Simplicity of Nature vs. Nurture". The Wall Street Journal.
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