Thursday, August 05, 2010

Witness credibility: exerpts from the Prop 8 ruling.

There was some (what appeared to me) important statements by Judge Walker in his ruling about the credibility of the various witnesses in this case. There is also a fair amount of really good reading on the various requirements for expert witness standing from the Federal Rules (this starts on page 39 of the ruling, and go until 41), a reminder or primer of what -- exactly -- makes a witness an expert witness in terms of testimony.

While Judge Walker First, his statements about the credibility of the plaintiff witnesses:
Having observed and considered the testimony presented, the court concludes that plaintiffs’ lay witnesses provided credible testimony:


As the education and experience of each expert show, plaintiffs’ experts were amply qualified to offer opinion testimony on the subjects identified. Moreover, the experts’ demeanor and responsiveness showed their comfort with the subjects of their expertise. For those reasons, the court finds that each of plaintiffs’ proffered experts offered credible opinion testimony on the subjects identified.
In contrast, the judge wrote of the proponents' actions and witnesses in a very different tone:
Proponents elected not to call the majority of their designated witnesses to testify at trial and called not a single official proponent of Proposition 8 to explain the discrepancies between the arguments in favor of Proposition 8 presented to voters and the arguments presented in court ... [since] they “were extremely concerned about their personal safety, and did not want to appear with any recording of any sort, whatsoever.” Tr 1094:21-23.

The timeline shows, however, that proponents failed to make any effort to call their witnesses after the potential for public broadcast in the case had been eliminated. ... The record does not reveal the reason behind proponents’ failure to call their expert witnesses.
and later, of the first of two witnesses the proponents did call:
For the reasons explained hereafter, Blankenhorn lacks the qualifications to offer opinion testimony and, in any event, failed to provide cogent testimony in support of proponents’ factual assertions.


Plaintiffs challenge Blankenhorn’s qualifications as an expert because none of his relevant publications has been subject to a traditional peer-review process, Tr 2733:2-2735:4, he has no degree in sociology, psychology or anthropology despite the importance of those fields to the subjects of marriage, fatherhood and family structure, Tr 2735:15-2736:9, and his study of the effects of same-sex marriage involved “read[ing] articles and ha[ving] conversations with people, and tr[ying] to be an informed person about it,” Tr 2736:13-2740:3. See also Doc #285 (plaintiffs’ motion in limine). Plaintiffs argue that Blankenhorn’s conclusions are not based on “objective data or discernible methodology,” Doc #285 at 25, and that Blankenhorn’s conclusions are instead based on his interpretation of selected quotations from articles and reports, id at 26.

The court permitted Blankenhorn to testify but reserved the question of the appropriate weight to give to Blankenhorn’s opinions. Tr 2741:24-2742:3. The court now determines that Blankenhorn’s testimony constitutes inadmissible opinion testimony that should be given essentially no weight.


Blankenhorn offered opinions on the definition of marriage, the ideal family structure and potential consequences of state recognition of marriage for same-sex couples. None of Blankenhorn’s opinions is reliable.


Blankenhorn gave no explanation of the methodology that led him to his definition of marriage other than his review of others’ work. The court concludes that Blankenhorn’s proposed definition of marriage is “connected to existing data only by the ipse dixit” of Blankenhorn and accordingly rejects it. See Joiner, 522 US at 146.


Blankenhorn’s conclusion that married biological parents provide a better family form than married non-biological parents is not supported by the evidence on which he relied because the evidence does not, and does not claim to, compare biological to non-biological parents. ... The studies may well support a conclusion that parents’ marital status may affect child outcomes. The studies do not, however, support a conclusion that the biological connection between a parent and his or her child is a significant variable for child outcomes. The court concludes that “there is simply too great an analytical gap between the data and the opinion proffered.” Joiner, 522 US at 146. Blankenhorn’s reliance on biology is unsupported by evidence, and the court therefore rejects his conclusion that a biological link between parents and children influences children’s outcomes.

To the extent Blankenhorn believes that same-sex marriage is both a cause and a symptom of deinstitutionalization, his opinion is tautological. Moreover, no credible evidence supports Blankenhorn’s conclusion that same-sex marriage could lead to the other manifestations of deinstitutionalization.


Neither of [the cited] sources supports Blankenhorn’s conclusion that same-sex marriage will further deinstitutionalize marriage, as neither source claims samesex marriage as a cause of divorce or single parenthood.


Blankenhorn had not seen [a scientific study that showed exactly the opposite findings of his deinstitutionalization claim] before trial and was thus unfamiliar with its methods and conclusions. Nevertheless, Blankenhorn dismissed the study and its results, reasoning that its authors “think that [the conclusion is] so self-evident that anybody who has an opposing point of view is not a rational person.” Tr 2918:19-21.

Blankenhorn’s concern that same-sex marriage poses a threat to the institution of marriage is further undermined by his testimony that same-sex marriage and opposite-sex marriage operate almost identically...

Blankenhorn gave absolutely no explanation why manifestations of the deinstitutionalization of marriage would be exacerbated (and not, for example, ameliorated) by the presence of marriage for same-sex couples. His opinion lacks reliability, as there is simply too great an analytical gap between the data and the opinion Blankenhorn proffered. See Joiner, 522 US at 146.

Blankenhorn was unwilling to answer many questions directly on cross-examination and was defensive in his answers. Moreover, much of his testimony contradicted his opinions.


Blankenhorn’s opinions are not supported by reliable evidence or methodology and Blankenhorn failed to consider evidence contrary to his view in presenting his testimony. The court therefore finds the opinions of Blankenhorn to be unreliable and entitled to essentially no weight.
Of the proponents' second witness, there was an initial argument as to his qualification of being an expert on the topic of the political power of gays and lesbians, but not his qualifications as to political science. However, the judge writes:
Having considered Miller’s background, experience and testimony, the court concludes that, while Miller has significant experience with politics generally, he is not sufficiently familiar with gay and lesbian politics specifically to offer opinions on gay and lesbian political power.


The credibility of Miller’s opinions relating to gay and lesbian political power is undermined by his admissions that he: (1) has not focused on lesbian and gay issues in his research or study; (2) has not read many of the sources that would be relevant to forming an opinion regarding the political power of gays and lesbians; (3) has no basis to compare the political power of gays and lesbians to the power of other groups, including African-Americans and women; and (4) could not confirm that he personally identified the vast majority of the sources that he cited in his expert report, see PX0794A. Furthermore, Miller undermined the credibility of his opinions by conceding that gays and lesbians currently face discrimination and that current discrimination is relevant to a group’s political power.

Miller’s credibility was further undermined because the opinions he offered at trial were inconsistent with the opinions he expressed before he was retained as an expert. Specifically, Miller previously wrote that gays and lesbians, like other minorities, are vulnerable and powerless in the initiative process, see PX1869 (Kenneth Miller, Constraining Populism: The Real Challenge of Initiative Reform, 41 Santa Clara L Rev 1037 (2001)), contradicting his trial testimony that gays and lesbians are not politically vulnerable with respect to the initiative process. Miller admitted that at least some voters supported Proposition 8 based on anti-gay sentiment. Tr 2606:11-2608:18.

For the foregoing reasons, the court finds that Miller’s opinions on gay and lesbian political power are entitled to little weight and only to the extent they are amply supported by reliable evidence.

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