||This article needs attention from an expert in Genetics. The specific problem is: This article gives too much emphasis on fringe theories pertaining to human intelligence. (June 2014)|
Dysgenics (also known as cacogenics) is the study of factors producing the accumulation and perpetuation of defective or disadvantageous genes and traits in offspring of a particular population or species. Dysgenic mutations have been studied in animals such as the mouse and the fruit fly. The term dysgenics was first used as an antonym of eugenics—the social philosophy of improving human hereditary qualities by social programs and government intervention.
Much of the debate regarding dysgenics has been about a hypothesized decline in intelligence due to lower fertility of the more intelligent. It is unclear how environmental factors may limit IQ differently in different populations. While there may be a correlation between IQ and lower fertility, it is unclear whether that would have any effect on intelligence over generations.
Dysgenics for other traits
In 1996, Richard Lynn wrote Dysgenics: Genetic Deterioration in Modern Populations. He identified three main concerns of eugenicists, such as himself: deterioration in health, intelligence and conscientiousness. Lynn argued that natural selection in pre-industrial societies favored traits such as intelligence and character but no longer does so in modern societies.
Lynn in a 1995 study of a sample of British criminal convicts found that they had an average fertility of 3.91 children. The general population had an average fertility of 2.1.
The word "dysgenic" was first used, as an adjective, about 1915, by David Starr Jordan, describing the dysgenic effect of World War I. Jordan believed that healthy men were as likely to die in modern warfare as anyone else, and that war killed only the physically healthy men of the populace whilst preserving the disabled at home.
Other counter-acting effects
Lynn and Harvey (2008) suggest that designer babies may have an important counter-acting effect in the future. Initially this may be limited to wealthy couples, who may possibly travel abroad for the procedure if prohibited in their own country, and then gradually spread to increasingly larger groups. Alternatively, authoritarian states may decide to impose measures such as a licensing requirement for having a child, which would only be given to persons of a certain minimum intelligence. The Chinese one-child policy is an example of how fertility can be regulated by authoritarian means.
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 and discovers 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 function has been replaced by automated systems in Idiocracy.
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