Man from the cradle is a racist. He prefers his own kind and turns up his nose, sometimes literally, at those from the next tribe. Or so, at least, argue evolutionary biologists. Human beings are hard-wired “to favor alliances . . . with others in direct proportion to degree of kinship and/or phenotypical similarity to these”; they display a “biologically based predisposition to have negative attitudes toward others on the basis of real or perceived differences that are typically, though not exclusively, of an ethnic nature.” Thus ethnic groups develop cultural markers to distinguish those who belong from those who do not. In her now famous “wise Latina” speech, for example, Judge Sonia Sotomayor said:
Not only the recognition but also the sharing of cultural markers can add to the appreciation of a novel, although sometimes I wonder if they are intended merely to create an alliance with some readers. In Thicker than Water, Vera Caspary’s 1932 novel about Sephardic Jews in Chicago, which I shall be reviewing at greater length in a few days, cultural references serve to differentiate one set of Jews from another, but since Caspary takes their differentiating force for granted and does not explain them further, they do double-duty as a signal of welcome to Jewish readers:
In more recent American fiction, ideological sloganeering does the cultural work of forging an alliance between writer and reader. In Bridge of Sighs, his weakest novel since his first novel, Richard Russo directs his first-person narrator to explain that his mother
This anxiety to win the approval of leftwing readers suggests to me that Russo, at least in The Bridge of Sighs, is a stranger to his own sensibility. A far more interesting passage occurs later in the novel when a Jewish mother confides that she does not believe in the sacramental conception of marriage. No surprise, really, since the Jewish conception is closer to that of a formal covenant. Russo appears not to know that. Instead, this is a slip—a simple failure of research. It reveals his cultural assumption—namely, that marriage is to be conceived in sacramental terms. When he is not trying to impress upon his readers that he shares their political opinions, Russo’s deepest instincts are Catholic.
Zoë Heller’s superb novel The Believers is all the more astonishing in this light. Since writing my review of it, I have learned that Heller is a Lefty. Yet she alludes to President Bush without winking broadly at her readers. Her allusion is poker-faced, neutral. For she is not interested in establishing her own ideological fides, but in showing in precise detail how ideology operates as a cultural marker separating her characters—especially Audrey, the self-described harridan and lifelong socialist—from those who are beneath their notice. The unavoidable conclusion is that ideology has little to do with ideas. Its real purpose is cultural: to sustain a feeling of kinship among those on the same side.
 Joseph Lopreato and Timothy Crippen, Crisis in Sociology: The Need for Darwin (New Brunswick, N.J.: Transaction, 1999), p. 267. Quoted in Russell K. Nieli, “Selling Merit down the River,” National Association of Scholars (July 6, 2009): 46–47.
 Vera Caspary, Thicker than Water (New York: Liveright, 1932), pp. 122–23.
 Richard Russo, Bridge of Sighs (New York: Alfred A. Knopf, 2007), p. 177.