Bearman and Bruckner: There is no fraternal birth order effect

Peter Bearman and Hannah Bruckner authored a paper in 2001 that was later published in the American Journal of Sociology, vol. 107, 1179-1205, 2002 which offers a major challenge to the recent fraternal birth order effect suggested by Anthony Bogaert. Bogaert’s research, published in the Proceedings of the National Academy of Science of the USA, suggests that having biological brothers, not non-biological ones (adopted, step-brothers) is the key to this effect, thus suggesting pre-natal factors, as yet undiscovered.

Those interested in this line of research should examine Bearman and Bruckner’s study which I believe to be very well done. They were also able to catch identical twin data and found low concordances for MZ, DZ and siblings. There were no significant differences between groups.

More on this paper later…

Hooker on parenting and homosexual orientation

You will have to click on this image to read the first page of this three page reaction By Evelyn Hooker to an article by Evans in the 1969, Journal of Consulting and Clinical Psychology. Hooker of course did the studies on homosexual men that are credited with providing basis for the 1973 removal of homosexuality from the DSM series. I am doing a review of studies on causality along with GCC prof Gary Welton and ran into this reaction from Hooker.

Note the first sentence: “It can no longer be questioned that faulty, disturbed, or pathological parental relationships in
early childhood are more commonly reported by male homosexual patients than by a comparable group of male heterosexuals.”

Of course, cause and effect are issues to wrestle with but I was surprised to read Hooker’s perspective here.

Pruden v. LeVay in the Salt Lake Trib: My response

David Pruden, Executive Director of Evergreen International and Simon LeVay, writer and neuroscientist had parallel op-eds in the Salt Lake Tribune this month about the origins and mutability of sexual orientation (click the links to read them). I submitted the following response to the trib, which was considered but turned down today for sunday’s paper. No word if it will end up in a future edition but I am going to post it anyway.

Sexual orientation: An interactionist’s view

The Tribune recently printed articles by David Pruden and Simon LeVay regarding sexual orientation. I want to present an alternative view.

I am more tentative about cause than either Mr. Pruden or Dr. LeVay. I disagree with Mr. Pruden that all researchers have abandoned the born gay view. Many researchers enamored with biological determinism continue to look for anything besides environment that could determine our sexuality. Sometimes their enthusiasm reminds me of the optimist cleaning the horse stall – “there must be a pony in here somewhere!”

On the other hand, Dr. LeVay is correct that biological factors cannot be dismissed. Corroborating research is required to learn how these factors operate but research consistently demonstrates small and subtle biological influences.

An alternative proposition incorporating biological and environmental factors is offered by Daryl Bem at Cornell University. He suggests that erotic attractions are not directly coded in genes, or wired in the brain via pre-natal hormones. Rather, biology may influence sexual orientation through the expression of childhood temperament (levels of aggression, eye-hand coordination, etc.), which are influenced by pre-natal factors. The most durable finding in years of research regarding homosexuality is that adult homosexuals recall gender atypical preferences as children (e.g., feminine boys, tomboyish girls). For instance, boys feeling different from other boys during childhood due to culturally feminine preferences may see males as the opposite sex just as puberty ushers in hormones and the accompanying unfocused sexual feelings.

While Dr. Bem’s theory awaits additional investigation, there is supporting research. One study found that neither genetic similarity nor a shared womb was associated with adult homosexual orientation unless childhood gender nonconformity was factored in. Even with this research, we must be tentative due to the observation that not all gays, especially lesbians, felt different from same-sex peers as children. The best we can say at present is that different factors, biological and environmental, may be relevant for different individuals. This would make sexuality akin to many human preferences, unchosen in the immediate sense, but acquired over time via an interaction of one’s nature and life’s nurture. Although difficult to fit into a headline, sexual orientation is more complex than “gay genes” versus “no gay gene.”

What ever “causes” sexual orientation, there is clear evidence that sexual orientation is somewhat flexible, at least for some. One recent study found that about one-third of participants reported spontaneous change in sexual orientation categories (e.g., gay to straight; bisexual to gay). Another one-third reported less dramatic change. These changes were naturalistic; no therapy was involved.

While Dr. LeVay is correct that sexual reorientation therapy does not lead to benefit for all clients, he is on shaky ground when he states: “By all accounts, the chances of “success” – if that is the right word – are far outweighed by the likelihood of experiencing lasting psychological trauma.” The results of research on change depend on what former clients are polled – some believe therapy helped and some do not. There is no research that can predict what percentage of people might benefit and what percentage might experience harm. We need more research not dogmatism.

However, no matter what causes various sexual desires, or how flexible they might be, humans are endowed with the capacity to reflect on their situations and direct their actions to live in alignment with their beliefs and chosen values. Scientific research on biological and social factors that are relevant to adult personality cannot be prescriptive. That is, science can tell us much about what is, but little about what we ought to believe. Many questions of public policy, or how we should relate to God are independent of what science might ever find out about our sexual proclivities.

Sourcing Sexuality – Webcast

Short notice but check out this webcast today (july 18 at 19:00pm in Britain) called Sourcing Sexuality, hosted by the Dana Centre. The program features discussion from Sven Bocklandt, geneticist, University of California, Los Angeles, Qazi Rahman, psychobiologist, University of East London and King’s College London and Jeffrey Weeks, Executive Dean of Arts and Human Sciences, London South Bank University. I am writing this as I wait for it to come on and the music playing is worth the visit.

UPDATE: Good program. The video will be available soon at the same link. When the Q & A came up, mine was the first question. It was:

Michael Bailey and colleagues in 2000 only found an 11% (for men) and 14% (for women) pairwise concordance homosexuality. These twins were reared together, shared the same womb and same genes.

Doesn’t this argue that chance is involved in sexual orientation outcomes? Different biological and environmental factors would be more dominant for different people. Thus, the search for the cause of sexual orientation is likely to always be frustrated by exceptions since there may be multiple pathways to sexual attractions.

I would hope that both social constructionist and biologically minded panelists could have a go at this question.

More later

UPDATE: I was going to say more about the program but it is supposed to be online within a couple of days. I think it was a valuable program for anyone interested in this issue so keep checking the website. Regarding my question, Sven Bocklandt said there are several twin studies, some with larger concordances but whatever they were, environment must play a role. The social constructionist, Jeffrey Weeks, indicated agreement with my statement.