Biological determinism

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Biological determinism, also known as genetic determinism is the belief that human behavior is 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. It has been associated with movements in science and society including eugenics, scientific racism, the debate around the heritability of IQ, the biological basis for gender roles, and the sociobiology debate. 

 

In 1892 August Weismann proposed in his germ plasm theory that heritable information is transmitted only via germ cells, which he thought contained determinants (genes). Francis Galton, supposing that undesirable traits such as club foot and criminality were inherited, advocated eugenics, aiming to prevent supposedly defective people from breeding. Samuel George Morton and 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 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.

Late in the 20th century, the determinism of gender roles was debated by geneticists and others. Biologists such as John Money and Anke Ehrhardt attempted to describe femininity and homosexuality according to then-current social standards; against this, the evolutionary biologist Richard Lewontin and others argued that clothing and other preferences vary in different societies. The 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.

History

Roots

Biological determinism is the belief that a human’s behavior is controlled by a person’s genes and inherited traits. It dates back to the 1800s. Stephen Jay Gould has spent his career tracing the roots of this “western” thought because it is more involved than anyone could have assumed. Gould suggests that the main theories of biological determinism are based on bad biology and bad use of the scientific method. When a scientist says they used the scientific method to gather their data, the readers automatically assume that the information given must be correct. 

Gould presents three key ideas that have influenced biological determinism. The first is that measurement and quantification have changed science over the past century and without context, these measurements are useless. If something is assigned a number, then it must be real, true, and scientific. If these numbers and measurements are given without context, then the data can be given many different meanings. The second is that reinfication, the idea that certain qualities (intelligence, race) are valid because we put a name on it. One could separate a group into different components and give a name to these divided groups and have it be true, but actually, there is nothing scientific about intelligence being used as a unitary quality. The third problem is that the main thought behind biological determinism is that traits are inherited. Scientists have traced certain traits through families lines and found that some are inherited. Gould suggests that these studies merely restate the original assumption. Gould points out that various theories of biological determinism have no evidence or science to back them up, and even though these ideas are very flawed, people still widely accept them. 

However, Gould is thought to be flawed in his own way because readers believe he is simply disregarding certain aspects of science. Gould questions that since the scientific aspects of the works themselves are so flawed that why is it so widespread accepted. Gould suggests that there could be some social, political, and economic forces which could explain why these biological determinism theories are so widely accepted, but he fails to go further deep into the topic. Gould shows that these biological determinism theories have many consequences for human life and scientists in the future can see these and use his book to continue trying to show the people that biological determinism, is in fact, false. 

In this review of Gould’s essay by Garland E. Allen, Allen writes that Gould has helped future scientists examine social, economic, and political values of this time regarding biological determinism. Biological determinism is still prominent in scientific works, past and present, that have been regarded by the public as true and believable. Gould wants his readers to understand that biological determinism has roots all throughout science, even though it has been proven false. 

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. 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.

Eugenics

The early eugenicist Francis Galton invented the term eugenics and popularized the phrase nature and nurture.

Early ideas of biological determinism centered 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.

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 colors, 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 gender roles

Lynda Birke argues in her 1992 book In Pursuit of Difference that biology explains sexual differences by the mechanisms of chromosomes, genetics, and inheritance. However, hormonal differences are not absolute, and people can be born with intersex characteristics, for example as a genetic mosaic. Homosexuality can be attributed to both biological and social causes. Dean Hamer has studied the so-called "gay gene". The neuroscientist Simon LeVay in 1991 studied the difference in hypothalamic structures between homosexual and heterosexual men, finding that the INAH-3 suggested a partial cause for homosexuality. Richard Lewontin, Steven Rose, and Leon Kamin's book Not in Our Genes discussed a study of girls who were relatively "masculinized". The biologists John Money and Anke Ehrhardt looked for ways to describe femininity that fitted their own social standards, such as clothing preference or using makeup. The experiment, in Lewontin's words, "ignores the existence of societies in which women wear pants, or in which men wear skirts, or in which men enjoy and appropriate jewelry to themselves." Gender differences in work are becoming less pronounced, suggesting that these are imposed by society. In contrast, the standard model of sex and gender indicates a clear-cut dichotomy between males and females, with no overlap, a cultural model followed by professionals such as doctors when they deal with gender assignment.

Sociobiology

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

 

Sociobiology emerged with E. O. Wilson's 1975 book Sociobiology: The New Synthesis. The existence of a putative altruism gene is debated. The evolutionary biologist W. D. Hamilton proposed "genes underlying altruism" in 1964. 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 behavior like "loving our neighbor" is built into the human genome, with the proviso that neighbor means member of "our tribe", someone who shares many genes with the altruist, and that the behavior can thus be explained by kin selection. Evolutionary biologists such as Jones have argued that genes that did not lead to selfish behavior would die out compared to genes that did, because the selfish genes would favor 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 has been matched 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 were expressed within an environment, in particular that of prenatal development, and that genes were continuously controlled by the environment through mechanisms such as epigenetics.