Did the Nazis Ban IQ Testing?

Scott Alexander recently claimed that:

the Nazis were so bad at race science that they banned IQ research after Jews outscored Aryans

I've seen variants of this claim before and it never seemed credible. Digging into it, I found that while some Nazis did criticize IQ tests, there was no formal ban. The broader point that some Nazis, like modern liberals, put their ideology above science in dismissing intelligence testing is correct.

The assertion that the Nazis banned IQ testing was made by Hans Eysenck in his 1979 book The Structure and Measurement of Intelligence:

Dictators, too, have been annoyed by the fact that the paradigm did not concur with their weird theories; thus Stalin banned IQ testing in the USSR for being bourgeois, and Hitler in Germany for being Jewish!

Alas, no source is provided. He made a similar claim in his 1973 work The Measurement of Intelligence, saying "Stalin, like Hitler, banned IQ testing for political reasons," but again, no source is provided. The phrasing leads to more questions. Did Hitler personally issue a decree forbidding IQ testing? Or was it someone in the educational or university bureaucracy?

According to the book "The Professionalization of Psychology in Nazi Germany," intelligence testing did come under criticism in Nazi Germany partly for political reasons, though it says nothing of a formal ban. Even critics found the tests useful in some situations:

The old psychotechnical methods and intelligence tests, which were under fire from characterologists anyway, were now attacked with new political arguments. Friedrich Becker, from Jaensch's school, criticized certain intelligence tests for favoring the "Jewish form of intelligence." These "cerebral-intellectual meddlings" were especially to the taste of the so-called dissolution type of cultural decline according to Jaensch (Becker 1938a, pp. 33, 94). Schliebe (1937, p. 198) took pains to emphasize that the aptitude tests then employed by the army, the railways, and others had nothing to do with the old "Jewish" psychotechnics. At the same time there were claims that psychotechnics (although this name was hardly used any more) could provide empirical foundations for the new ideological doctrines. Giese expressed this opinion at the fourteenth congress of the DGfPs in 1934; by comparing the typical performance and function ideals of the German "tribes" and their value systems, it would be possible to develop an empirically based mental study of tribes and then "to publicly propagate the tribalpsychological evaluation of the German people" (1935, p. 202)."

{snip}

In practice this attitude was seen at its clearest in the use of classical methods of aptitude diagnosis for the selection of foreign workers during the war (cf. Chapter 4). This involved intelligence tests (involving simple tests of logic, combinatorial ability, and calculations), spatial perception (e.g., with Rybakov figures), cog wheel tests for technical understanding, and wire bending to establish manual dexterity (Schorn 1942). The ten simple intelligence questions initially used were based on the U.S. Army mental tests used in the First World War. In Becker's work just quoted these tests did not come off quite as badly as the "Jewish" methods, even though they did give an advantage to the dissolution type. However, Becker (1938a, p. 85) had picked out the Rybakov figures as tasks typifying the "frivolous," "unrealistic" intelligence of the dissolution type. Nevertheless, the test was used for selecting out deported and prisoner-of-war workers. This was because "they can be carried out quickly... and protect the firms from making severe mistakes," as the newsletter of the Amt Bub put it.17 In a pamphlet written for use in factories entitled "Selection and Deployment of Eastern Workers," a district chief for technology praised the advantages of psychotechnical selection (using this term) in the stark language of the technologist. The psychotechnical selection of deportees was recommended "when these people are to be used for more difficult tasks, which require a certain degree of technical ability, speed of reaction etc." (Haas 1944, p. 24). They met the need for tests that were "flexible, cheap and short"{snip}

The criticisms by Becker and Jaensch echo modern criticisms of IQ tests. From Heiner Rindermann's 2018 book Cognitive Capitalism:

Contradicting common beliefs, National Socialists were opposed to intelligence research (Becker, 1938; Jaensch, 1938): in their view, intelligence research would represent a 'supremacy of Bourgeoisie spirit' (Jaensch, 1938, p. 2); intelligence measurement would be an instrument 'of Jewry' to 'fortify its hegemony' (p. 3); selection in schools according to intelligence would stand for a 'system of examination of Jewish origin' (p. 4), especially the concept of intelligence as a 'one-dimensional dimension' (p. 3) and 'one common central factor' (Becker, 1938, p. 24). Because people differ and therefore intelligence differs (p. 4) they called for an 'intelligence measurement according to a national and typological point of view' (p. 15); for Germans they asked for a measurement of 'realism', 'conscientiousness' and 'actually of the character value of intelligence'. They were opposed to a measurement solely of 'theoretical intelligence', of 'intellectualism' (Becker, 1938, p. 22); instead they favoured 'practical intelligence' (p. 18) that should be measured. Nazi researchers were opposed to the methods of correlation and factor analysis (p. 23f.); general intelligence did not exist: 'In fact there is no general, qualitatively comparable and from type independent intelligence.' (Jaensch, 1938, p. 4)

If the term 'Jewish' were exchanged for 'dominant class' we would have the same critique as mentioned by Bourdieu, only 40 years earlier and developed by the National Socialists. And the critique from the 'left' of today against cross-cultural intelligence comparisons, incomparability, bias, g factor etc. was also first mentioned by the National Socialists.

It should be noted that these debates were conducted at academic conferences and in academic journals. It's not like Hitler, Goebells, or Rosenberg were saying these things. Jaensch only became a Nazi in 1932, a year before the Nazi rise to power, in what may well have been an opportunistic career move. (He became a financial supporter of the SS in 1932 and joined the party in 1933.) Unease with IQ testing was not central to Nazism the way it is to modern woke ideology.