dysgenics

Dysgenics (also known as cacogenics) is the study of factors producing the accumulation and perpetuation of defective or disadvantageous genes and traits in offspring in a particular population or species.^[1][2] Dysgenic mutations have been studied in animals such as the mouse^[3] and the fruit fly.^[4][5] The term dysgenics was first used as an antonym of eugenics — the social philosophy of improving human hereditary qualities via social programs and government intervention. ^[6]

History

"Dysgenic" was first used, as an adjective, around 1915, by David Starr Jordan, describing the "dysgenic effect" of World War I.^[7] Jordan believed that fit men were as likely to die in modern warfare as anyone else, and that war killed only the physically fit men of the populace whilst preserving the disabled at home.^[8][9]

In 1965, Colum Gillfallen speculated in The Mankind Quarterly that lead used by Romans in plumbing and cooking utensils poisoned the water and food of the Roman elite, causing the decline of the Roman Empire.^[10] Gillfallen's theory was refuted in 1985 by Needleman and Needleman, who showed that measurements of lead from bones of Romans and other peoples provide no evidence that the fertility of the Roman elite was adversely affected.^[11]

William Shockley used the term in his controversial advocacy of eugenics from the mid-1960s through the 1980s. Shockley argued that "the future of the population was threatened because people with low IQs had more children than those with high IQs."^[12][13]

Robert Klark Graham in 1998 argued that genocide and class warfare, in cases ranging from the French Revolution to the present, have had a dysgenic effect through the killing of the more intelligent by the less intelligent, and "might well incline humanity toward a more primitive, more brutish level of evolutionary achievement."^[14]

Since 1969, a few studies on differential fertility have theorized that it may lead to a decline in population IQ and isolated studies have reported a negative correlation between IQ and fertility.^[15][16][17] In 1996, Richard Lynn wrote Dysgenics: Genetic Deterioration in Modern Populations; Lynn had been previously criticized for distorting and misrepresenting data^[18][19][20] although others have favorably reviewed Lynn's work on dysgenics.^[21][22][23] Richard Lynn (along with Daniel R. Vining and William Shockley) is a major recipient of grants from the Pioneer Fund, characterized as a hate group by the Southern Poverty Law Center (SPLC),^[24][25] a civil rights advocacy organization.

Flynn effect

The rise in IQ scores since their^[who?] development provides evidence against dysgenic declines in IQ; this general rising trend is known as the Flynn effect. Geneticist Steve Connor wrote that Lynn, writing in Dysgenics: Genetic Deterioration in Modern Populations, "misunderstood modern ideas of genetics." "A flaw in his argument of genetic deterioration in intelligence," Jones said in his refutation of the existence of a dysgenic trend, which "was the widely accepted fact that intelligence as measured by IQ tests has actually increased over the past 50 years."^[26]

If the genes underlying IQ have been shifting, IQ throughout the population should reasonably be expected to shift in the same direction, yet the reverse has occurred. However, genotypic IQ may fall even while phenotypic IQ rises throughout the population due to environmental effects such as better schooling, nutrition, and television viewing.^[27] The Flynn effect has increased IQ scores as much as 15 points throughout the First World, but some researchers have argued that this trend now shows signs of reversal.^[28][29]

Flynn himself has recently argued that the Flynn effect does not show a real increase in intelligence over time, as if it were so, then intelligence in past centuries would be implausibly low. Instead, he believes the effect is due to a bias in IQ tests towards abstract reasoning, which has improved during the 20th century due to education and technology. People in past centuries perhaps had similar intelligence to those today, but were not as proficient at abstract reasoning.^{[citation needed]}

Dysgenic fallacy

A negative correlation between fertility and IQ has existed in many parts of the world at various times;^[30] it has been argued that this was true of Ancient Rome.^[11] While it may seem obvious that differential fertility would result in a progressive change in IQ, Preston and Campbell argue that it is a fallacy that applies only to closed subpopulations. As long as the children's IQ can be higher or lower than that of their parents, an equilibrium is established. Subsequently, the mean IQ will not change in the absence of a change in the differential fertility. The steady-state IQ distribution will be lower for negative differential fertility and for positive, but these differences are small. For the extreme, and unrealistic assumption, of endogamous mating in IQ subgroups, a differential fertility change of 2.5/1.5 to 1.5/2.5 (high IQ/low IQ) causes a maximum shift of four IQ points. For random mating, the shift is less than one IQ point.^[31]

James S. Coleman, however, contends that Preston and Campbell's model depends on assumptions which are unlikely to be true, and argues that their dismissal of the "common belief" in the case of IQ is unfounded.^[32][33]

In fiction

Cyril M. Kornbluth's 1951 short story The Marching Morons is an example of dysgenic fiction, describing a man who accidentally ends up in the distant future to find out that dysgenics has resulted in mass stupidity. Mike Judge's 2006 film Idiocracy has the same premise, with the main character the subject of a military hibernation experiment that goes awry, taking him 500 years into the future. While in the Kornbluth short story civilization is kept afloat by a small group of dedicated geniuses, their role has been replaced by automated systems in Idiocracy.^[34][35]

See also

• Breeder (slang)
• Devolution (biological fallacy)
• Degeneration
• Societal collapse
• Social Darwinism

Related:

• List of congenital disorders
• Fertility and intelligence
• Heritability of IQ

Notes