NARTH, the New Epigenetic Model and Confirmation Bias

Last week, I wrote briefly about the new paper from William Rice et al which describes an epigenetic model of homosexuality. In that post I reported a quote from National Association for the Research and Therapy of Homosexuality (NARTH) spokesman David Pruden regarding the study. Here is Pruden’s statement which was cited in the Christian Post:

“The theoretical model itself attributes only 10-14 percent of the factors to genetics or epigenetics. That leaves the remaining 85 percent or so of the factors to environmental influences,” said Pruden.

That assessment did not sound right to me so I contacted William Rice who informed me that his model accounted for homosexuality generally speaking, not just for “10-14 percent.” The Christian Post rightly printed the correction at the end of the article.

So where did the 10-14 percent figure come from? According to an email from Pruden, that range came from NARTH Scientific Advisory Board member, Neil Whitehead. Whitehead has speculated in the past that the maximum genetic contribution is between 10-14%. While I believe his assessment is low, he has referred to various studies to provide support. However, in the case of the new study, it appears no one at NARTH has even read the paper.

If Pruden read it, he didn’t refer to it. Rather he referred to Whitehead who yesterday placed a brief article on the NARTH website about the paper. Here is the body of Whitehead’s statement:

(A  fuller evaluation will appear here on this site: when the full paper is available)

Recently (Anonymous, 2012) a summation of a published paper (Rice, W.R., Friberg, U. Gavrilets,  2012) has  achieved attention as being an explanation for homosexuality.

Readers should note this is a theoretical model only and  that  historically many theories have been put forward as the single overriding factor  causing homosexuality.  The current best consensus is that there is no single over-riding factor – the  trait is multifactorial and overwhelmingly environmental. The Rice paper is quite unlikely to be “critical”. Like previous  theories, the current epigenetic one may well have a small contribution, but  this remains to be established. The authors themselves  note that laboratory work has yet to be done. The paper built on  previously published work (Rice, Gavrilets, & Friberg,  2008).

Apparently, Whitehead has not read the paper because he said the “full paper” was not available. On the contrary, the paper is freely available online here.

What is striking is what Whitehead says about the topic of the paper before seeing it. He says homosexuality is “overwhelmingly environmental” and opines that the current epigenetic theory is unlikely to make more than a “small contribution” to homosexuality. It appears that Pruden and Whitehead have their minds made up.

NARTH is so committed to an environmental/family model of cause that organization leaders jump to a preferred conclusion before even considering the evidence.  This is one way confirmation bias operates. In this case, NARTH representatives said things about the theory before they read or studied it, and what they said came, not from the paper, but from their preconceived ideas.