All too often during discussion of the cause of transgenderism, we hear the argument that scientists have proven that transgenderism is not caused by genes. This is certainly false as significant genetic evidence has been found, but that evidence is not what I want to discuss here. Rather, I want to point out the bait and switch that happens where "genetic cause" is swapped with "genetic determination." Some events have only one cause; we call this cause a determination. However many events have multiple causes. Genes are rarely deterministic. A few traits like eye and hair color are determined by a single gene, but these are the exceptions. A trait like height is caused by genes, age, nutrition and other factors. In these cases we say the gene does not determine height but predisposes us to a height. Researchers are unanimous that if a genetic cause for transgenderism exists, the gene predisposes us to a gender identity. Let's look at a example in Transsexuality A Report by the Evangelical Alliance Policy Commission, page 19-20.
However, no research has been able to demonstrate the existence of such a 'transsexual gene.' [Footnote:] In this connection, if transsexuality were to be a purely genetic condition, it could be expected, for example, that in the case of identical twins (who have exactly the same genes) if one was transsexual, the other would be also. This, however, has not been demonstrated by any known research. [Concludes with several references.]
Here we see that the body of the text states that no research demonstrates a genetic cause but the footnote and references relate only to genetic determination. The reader is led to believe causality and determination are one and the same. Neil Whitehead makes the same error, and he's supposed to be an expert!
Identical twins , having identical genes and identical environment, should have identical transsexuality; if not, unique individual experiences are responsible. (Whitehead's Free Endorsement)