concurring.
I join fully Mr. Justice Blackmun’s sensitive opinion for the Court. I feel compelled to write separately, however, to express my profound disagreement with the views expressed by Mr. Justice Powell in his dissent.
As my Brother Powell observes, post, at 507-508, there are three categories of evidence in this case that bear on the ultimate question whether respondent “demonstrated by a preponderance of the evidence that the State had 'deliberately and systematically den[ied] to members of [respondent’s class] the right to participate as jurors in the administration of justice,’ ” post, at 517, quoting Alexander v. Louisiana, 405 U. S. 625, 628-629 (1972). First, there is the statistical evidence. That evidence reveals that for at least 10 years, Mexican-Americans have been grossly underrepresented on grand juries in Hidalgo County. As Mr. Justice Blackmun demonstrates, ante, at 496-497, n. 17, it is all but impossible that this sizable disparity was produced by chance. The statistical evidence, then, at the very least supports an inference that Mexican-Americans were discriminated against in the choice of grand jurors.
Second, there is testimony concerning the grand jury selection system employed in this case. That testimony indicates that the commissioners who constructed the grand jury panels *502had ample opportunity to discriminate against Mexican-Americans, since the selection system is entirely discretionary and since Spanish-surnamed persons are readily identified. Indeed, for over 35 years this Court has recognized the potential for abuse inherent in the Texas grand jury selection plan. See Smith v. Texas, 311 U. S. 128, 130 (1940); Hill v. Texas, 316 U. S. 400, 404 (1942); Cassell v. Texas, 339 U. S. 282, 289 (1950); Hernandez v. Texas, 347 U. S. 475, 479 (1954). Thus the testimony concerning the selection system, by itself, only buttresses the inference of purposeful discrimination suggested by the statistics.
In every other case of which I am aware where the evidence showed both statistical disparity and discretionary selection procedures, this Court has found that a prima facie case of discrimination was established, and has required the State to explain how ostensibly neutral selection procedures had produced such nonneutral results. This line of cases begins with the decision almost a century ago in Neal v. Delaware, 103 U. S. 370 (1881), and extends to our recent decision in Alexander v. Louisiana, supra.1 Yet my Brother Powell would have us conclude that the evidence here was insufficient to establish purposeful discrimination, even though no explanation has been offered for the marked underrepresentation of Mexican-Americans on Hidalgo County grand juries.
*503The sole basis for Mr. Justice Powell's conclusion lies in the third category of evidence presented: proof of “the political dominance and control by the Mexican-American majority in Hidalgo County,” post, at 507-508. Like the District Court, he appears to assume—without any basis in the record—that all Mexican-Americans, indeed all members of all minority groups, have an “inclination to assure fairness” to other members of their group. Post, at 516. Although he concedes the possibility that minority group members will violate this “inclination,” see post, at 514-515, n. 6, he apparently regards this possibility as more theoretical than real. Thus he would reject the inference of purposeful discrimination here absent any alternative explanation for the disparate results. I emphatically disagree.
In the first place, Mr. Justice Powell’s assumptions about human nature, plausible as they may sound, fly in the face of a great deal of social science theory and research. Social scientists agree that members of minority groups frequently respond to discrimination and prejudice by attempting to disassociate themselves from the group, even to the point of adopting the majority’s negative attitudes towards the minority.2 Such behavior occurs with particular frequency among members of minority groups who have achieved some measure of economic or political success and thereby have gained some acceptability among the dominant group.3
*504But even if my Brother Powell’s behavioral assumptions were more valid, I still could not agree to making them the foundation for a constitutional ruling. It seems to me that especially in reviewing claims of intentional discrimination, this Court has a solemn responsibility to avoid basing its decisions on broad generalizations concerning minority groups. If history has taught us anything, it is the danger of relying on such stereotypes. The question for decision here is not how Mexican-Americans treat other Mexican-Americans, but how the particular grand jury commissioners in Hidalgo County acted. The only reliable way to answer that question, as we have said so many times,4 is for the State to produce testimony concerning the manner in which the selection process operated. Because the State failed to do so after respondent established a prima facie case of discrimination, I join the Court’s opinion affirming the Court of Appeals.
See also Norris v. Alabama, 294 U. S. 587 (1935); Hale v. Kentucky, 303 U. S. 613 (1938); Pierre v. Louisiana, 306 U. S. 354 (1939); Smith v. Texas, 311 U. S. 128 (1940); Hill v. Texas, 316 U. S. 400 (1942); Patton v. Mississippi, 332 U. S. 463 (1947); Cassell v. Texas, 339 U. S. 282 (1950); Hernandez v. Texas, 347 U. S. 475 (1954); Eubanks v. Louisiana, 356 U. S. 584 (1958); Arnold v. North Carolina, 376 U. S. 773 (1964); Whitus v. Georgia, 385 U. S. 545 (1967); Jones v. Georgia, 389 U. S. 24 (1967); Sims v. Georgia, 389 U. S. 404 (1967); Turner v. Fouche, 396 U. S. 346 (1970).
In Akins v. Texas, 325 U. S. 398 (1945), the statistical evidence involved only two grand jury panels; in Swain v. Alabama, 380 U. S. 202 (1965), the statistical disparity was small, and the methods of selection were explained.
G. Allport, The Nature of Prejudice 150-153 (1954); A. Rose, The Negro’s Morale 85-95 (1949); G. Simpson & J. Yinger, Racial and Cultural Minorities 192-195, 227, 295 (4th ed. 1972); Bettelheim, Individual and Mass Behavior in Extreme Situations, 38 J. Abnormal & Social Psych. 417 (1943); cf. Brown v. Board of Education, 347 U. S. 483, 494, and n. 11 (1954) (noting the impact on sense of self of de jure segregation in schools).
E. Frazier, Black Bourgeoisie 213-216 (1957); Simpson & Yinger, supra, at 209; A. Kardiner & L. Ovesey, The Mark of Oppression 313-316 (1962); Lewin, Self-Hatred Among Jews, 4 Contemporary Jewish Record 219 (1941).
E. g., Norris v. Alabama, supra, at 592; Pierre v. Louisiana, supra, at 361; Alexander v. Louisiana, 405 U. S., at 631.