Human self-domestication / Martin Brüne

Open Access

On human self-domestication, psychiatry, and eugenics

Philosophy, Ethics, and Humanities in Medicine 20072:21

DOI: 10.1186/1747-5341-2-21

© Brüne; licensee BioMed Central Ltd. 2007


The hypothesis that anatomically modern Homo sapiens could have undergone changes akin to those observed in domesticated animals has been contemplated in the biological sciences for at least 150 years. The idea had already plagued philosophers such as Rousseau, who considered the civilisation of man as going against human nature, and eventually “sparked over” to the medical sciences in the late 19th and early 20th century. At that time, human “self-domestication” appealed to psychiatry, because it served as a causal explanation for the alleged degeneration of the “erbgut” (genetic material) of entire populations and the presumed increase of mental disorders. (This is a misconception on the part of psychiatry and medicine, and in itself does not prove-disprove self-domestication- me)

Consequently, Social Darwinists emphasised preventing procreation by people of “lower genetic value” and positively selecting favourable traits in others. Both tendencies culminated in euthanasia and breeding programs (“Lebensborn”) during the Nazi regime in Germany. Whether or not domestication actually plays a role in some anatomical changes since the late Pleistocene period is, from a biological standpoint, contentious, and the currently resurrected debate depends, in part, on the definitional criteria applied.

However, the example of human self-domestication may illustrate that scientific ideas, especially when dealing with human biology, are prone to misuse, particularly if “is” is confused with “ought”, i.e., if moral principles are deduced from biological facts. Although such naturalistic fallacies appear to be banned, modern genetics may, at least in theory, pose similar ethical problems to medicine, including psychiatry. In times during which studies into the genetics of psychiatric disorders are scientifically more valued than studies into environmental causation of disorders (which is currently the case), the prospects of genetic therapy may be tempting to alter the human genome in patients, probably at costs that no-one can foresee.

In the case of “self-domestication”, it is proposed that human characteristics resembling domesticated traits in animals should be labelled “domestication-like”, or better, objectively described as genuine adaptations to sedentism. (Agreed – me)


The term “domestication” refers to a goal-directed process through which humans have changed physical features of plants and animals by replacing natural through artificial selection to adapt these species to specific human needs. In animals, domestication-associated changes also include behavioural characteristics, which, above all, have led to a reduction of aggression and an increase of “tameness” [1]. At least since Darwin’s pioneering work on domestication [2], biologists have controversially debated whether several aspects of domestication-induced traits in animals could similarly be present in humans, and this issue has recently been reconsidered [1, 3]. Even earlier, however, philosophers have been plagued with the question of man’s place in nature. Jean-Jacques Rousseau (1755), for instance, had argued that “civilised” living conditions would have negative consequences, subsumed under the term “degeneration” [4]. Conversely, in the 1940s, the German philosopher Arnold Gehlen proposed a self-domestication theory of Homo sapiens, according to which domestication would, on one hand, induce biological maladaptedness through abandoning natural selection, but, on the other hand, open new prospects for cultural development [5]. Similarly, recent humanism has highlighted the positive aspects of a presumed human domestication such as to prevent “brutalisation” of human societies (comment in [6]).

Whereas philosophers have extensively discussed putative effects of human self-domestication in terms of moral values, by the turn of the 20th century psychiatrists became interested in the hypothesis of human self-domestication, because it seemingly provided a causal explanation for what was perceived as signs of degeneration of the human genepool (“erbgut”) (Again, a concept promoted by practitioners of psychiatry and medicine, and not a scientific effort into the proof-disproof of self-domestication. ) [7].

In 1857, the French psychiatrist Benedicte Morel sought to introduce objective measures in support of the concept of “degeneration”, suggesting that subtle physical abnormalities would indicate the deterioration of mental health and also account for delinquent behaviour, because such deviations would be most prevalent in mentally ill and criminals [8]. Indeed, by the turn of the 20th century, with increasing biologising of psychiatry, leading professionals were concerned about the seemingly rising number of hospitalised patients and searched for biological explanations, leaving aside social factors [9]. Hence, the hypothesis of the domestication of man was welcome, and, in light of the then prevailing cultural pessimism and upcoming eugenic idealism put forth by August Forel and Alfred Ploetz [10], readily adopted as rationalisation of a host of unresolved questions in psychiatry and related social issues. It is perhaps not exaggerated to state that this one-sided biological view of mental disorders and handicaps also contributed to what followed in Germany under the Nazi regime.

Albeit modern human biology may be largely free of moral allegations, there seems to be a need for discussing the possible impact of biological findings and hypotheses on contemporary conceptualisations of mental health and treatment options of psychiatric disorders. This premise is based on the fact that biological ideas have always been at risk of socio-political misuse, (and I contend that this is exactly what is happening in ASD and Asperger research and diagnosis) and on the concern that the advent of new genetic techniques may be tempting to “improve” human genetic material and eliminate unwanted traits, part of which could erroneously be attributed to human self-domestication.

In this article, I shall (1) deal with the biological evidence for human self-domestication and the historical development of the idea, including its entanglement with political opportunism during the Nazi epoch in Germany; (2) outline how and why the self-domestication hypothesis was adopted by leading (German) psychiatrists, and possibly contributed to positive and negative selection programs during the Third Reich in Germany; (3) finally argue that the debate between philosophy, biology, and other medical sciences including psychiatry necessitates a common language for further interdisciplinary exchange of ideas, as well as awareness of the dangers of naturalistic fallacies. (Halleluiah! It’s about time!)

More next post…..

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