“The fact that a reasonable hypothesis has not been rigorously proved does not mean that it should be summarily dismissed. It only means that we need more appropriate research for putting it to the test. I believe such definitive research is entirely possible but has not yet been done. So all we are left with are various lines of evidence, no one of which is definitive alone, but which, viewed all together, make it a not unreasonable hypothesis that genetic factors are strongly implicated in the average Negro-white intelligence difference. The preponderance of the evidence is, in my opinion, less consistent with a strictly environmental hypothesis than with a genetic hypothesis, which, of course, does not exclude the influence of environment or its interaction with genetic factors.”
p. 82 of How Much Can We Boost IQ and Scholastic Achievement? (1969) https://en.wikipedia.org/wiki/How_Much_Can_We_Boost_IQ_and_Scholastic_Achievement%3F, the invited paper that created much hostility towards Jensen.
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Arthur Jensen 11
professor of educational psychology 1923–2012Related quotes

Source: Are We Getting Smarter?: Rising IQ in the Twenty-First Century (2012), p. 36, Box 4

Source: 1840s, The Sickness unto Death (July 30, 1849), pp. 114 - 115

The Art of Persuasion

Source: Race, IQ, and Jensen (1980), pp. 40, 54. Quoted from Nevin Sesardic, Making Sense of Heritability (2005), p. 136.

(...) De nouvelles connaissances conduisent à reconnaître dans la théorie de l'évolution plus qu'une hypothèse. Il est en effet remarquable que cette théorie se soit progressivement imposée à l'esprit des chercheurs, à la suite d'une série de découvertes faites dans diverses disciplines du savoir. La convergence, nullement recherchée ou provoquée, des résultats de travaux menés indépendamment les uns des autres, constitue par elle même un argument significatif en faveur de cette théorie.
early news reports mistranslated the French phrase plus qu'une hypothèse as "more than one hypothesis". http://www.cartage.org.lb/en/themes/sciences/LifeScience/PhysicalAnthropology/EvolutionFact/Evolution/Evolution.htm
Message to the participants in the Plenary of the Pontifical Academy of Sciences, 22 October 1996
Source: Libreria Editrice Vaticana http://www.vatican.va/holy_father/john_paul_ii/messages/pont_messages/1996/documents/hf_jp-ii_mes_19961022_evoluzione_fr.html (French)
Richard Cyert, James G. March, William H. Starbuck. (1961) "Two experiments on bias and conflict in organisational estimation," Management Science, 254–64; Abstract