A small sect or society amidst a greater are commonly most regular in their morals; because they are more remarked, and the faults of individuals draw dishonour on the whole. The only exception to this rule is, when the superstition and prejudices of the large society are so strong as to throw an infamy on the smaller society, independent of their morals. For in that case, having no character either to save or gain, they become careless of their behaviour, except among themselves.--David Hume "Of National Characters," note 7.
David Hume's "Of National Characters" is notorious for dividing the human species into two: "I am apt to suspect the negroes to be naturally inferior to the whites." In Hume's hand's natural inferiority entails a kind of inherent limit to the (to adopt an Aristotelian phrase) second-nature produced by social (Hume calls them "moral") causes such as institutions, norms, trade(s), and other cultural practices that fix and stabilize individual habits and thereby the collections composed of these individuals. This limit is purportedly characterized by an absence of cognitive or intellectual excellence not just at the collective level but even among the individuals that are part of the naturally inferior race(s). [I am using 'race' here in its nineteenth century sense, but Hume is clearly one of the sources of the later use. (See also this post on Berkeley.)] This means that Hume's racial theory is untenable empirically on its own terms the moment it is confronted with evidence of African civilization and learning. As it happens, and to his eternal discredit, Hume also has a further tendency to discount such evidence that goes against his theory: "In JAMAICA, indeed, they talk of one negroe as a man of parts and learning; but it is likely he is admired for slender accomplishments, like a parrot, who speaks a few words plainly." Hume's stance is especially remarkable because as I first learned from Justin Smith, Anthony William Amo, at one point a professor in Halle and Jena, was already famous among the educated in Europe.
As an aside, Hume is a critic of slavery, so Hume is not following Aristotle in thinking that natural inferiority entails natural slavery. (It's likely he does so not on grounds of justice, but rather on grounds of humanity.) But Hume probably thinks that civilization -- that is being law-governed and obtaining the fruits thereof -- is not indigenous among the naturally inferior and this almost certainly explains his favorable attitude toward the martial exportation of civilization to the Welsh, Irish, and further colonies. This much is well known among careful students of Hume.
By contrast, on Hume's account, natural superiority merely entails that intellectual and cognitive excellence is possible among the race and also that once attained it can be lost in the next generation (due to lack of education or changing cultural or political circumstances): As he writes "The races of animals never degenerate when carefully tended; and horses, in particular, always show their blood in their shape, spirit, and swiftness: But a coxcomb° may beget a philosopher; as a man of virtue may leave a worthless progeny." The previous sentence also entails that the human species is different from other animals on Hume's account: external character traits are more fixed in animals through inheritance than in humans. (This reminds us that one should be cautious in seeing in Hume too much of an anticipation of Darwin.)
Among the naturally superior Hume makes a further demographic assumption: "though nature produces all kinds of temper and understanding in great abundance, it does not follow, that she always produces them in like proportions, and that in every society the ingredients of industry and indolence, valour and cowardice, humanity and brutality, wisdom and folly, will be mixed after the same manner." So, while Hume is pretty clear that social (so-called "moral") causes -- recall, institutions, norms, trade(s), and other cultural practices that fix and stabilize individual habits -- predominate in explaining average, national character-traits, individual variation is at least in part due to further innate talents. Moreover, different communities (or populations) may have a different distribution of such innate talents between each other and within each other in different generations.
Only "negroes" are classed among the "naturally inferior" in Hume. So "white" is not isomorphic to naturally superior because there is no doubt that for Hume the Chinese (a civilized nation) also belong among the superior. But it does not follow that natural superiority exempts one from negative stereotype in Hume's hands. His attitude toward Jews, who as an educated and commercial people belong to the superior kind, is, in fact, illustrative of this. To be clear Hume does not condone violence toward the Jews (as is clear from his treatment of the London massacre of them in his History). But as Langmuir noted, it's not like Hume is especially warm toward the Jews.
About the Jews of his own time "JEWS in EUROPE," Hume reports in "Of National Character" that they are "noted for fraud." Now, Hume's phrasing is compatible with him not agreeing in the judgment. (He may just be reporting other people's views.) But while Hume acknowleges that the uneducated ("the vulgar") "are apt to carry all [judgments of] national characters to extremes; and having once established it as a principle, that any people are knavish, or cowardly, or ignorant, they will admit of no exception, but comprehend every individual under the same censure." It turns out that the more educated, who "condemn these undistinguishing judgments," still maintain that national stereotypes are on average true: ",they allow, that each nation has a peculiar set of manners, and that some particular qualities are more frequently to be met with among one people than among their neighbours." [This is not the place to discuss how Hume treats generalizations that allow for exceptions, but I will note that such generalizations are central to Hume's explanatory enterprise--something that is missed if one comes to Hume through the treatment of miracles or causation in the first Enquiry.]
A small sect or society amidst a greater are commonly most regular in their morals; because they are more remarked, and the faults of individuals draw dishonour on the whole. The only exception to this rule is, when the superstition and prejudices of the large society are so strong as to throw an infamy on the smaller society, independent of their morals. For in that case, having no character either to save or gain, they become careless of their behaviour, except among themselves.
There are two mechanisms described by Hume here: first, members of minority communities are more robustly moral than majorities. It is not entirely clear what produces such (positive) conformity (or 'model minority'). It could be because the group polices itself more robustly because of fear of dishonor or because individuals are afraid to embarrass/shame their communities. Second, minority communities become less moral than the majority as a consequence of a false (!) stereotypes of the majority (Hume is clear it's false at first because of his use of 'superstition and prejudices'); it then becomes a self-fulfilling prophecy. On Hume's account the Jews fit the second mechanism: they are reliable among each other and more or less correctly noted for fraud among the general population.
Remarkably, then, Hume seems to have discerned and partially described the mechanism of stereotype threat, and still endorsed the judgments that are the product of it.