The Rev Rob McKay perpetuates an example of outdated religious attitudes to sexuality in his appeal to science for support. Nature/nurture issues were settled decades ago and the debate has moved on.
Academics now agree that both nature and nurture and their interaction make us what we are, and those who try to turn back the clock and insist any human behaviour is almost entirely nature or almost entirely nurture are maverick, and paying more attention to activism than science.
A far better summary is: "Genes create a tendency, not a tyranny" and "You can foster or foil any genetic tendencies". If one member of an identical twin pair is homosexual, there is only an 11 per cent chance the other twin is. That 11 per cent concordance results from a combination of genes plus upbringing, so we see that neither is overwhelming.
So it is genes plus upbringing which create a tendency, not a tyranny.
Identical twins have identical genes, and essentially identical upbringing.
The other important factor is chance, which has a strong effect on us because random events are often unusual and memorable. Note that these twin studies incorporate the influences of all factors combined, including those we are yet to discover.
The net effect is 11 per cent concordance. We will never, therefore, discover some factor which will negate this conclusion.
Homosexuality is only one well-studied example of many. Studies of identical twins for masculinity/femininity, transsexuality, leadership, drug addiction, alcoholism, novelty-seeking, suicide, extraversion, schizophrenia, altruism, depression, fundamentalism and so on only rarely produce concordance near 100 per cent for less common traits.
This argument usually arises because the experience of people is that it can be very hard to change some trait (for instance, alcoholism), therefore it is tempting to say it is innate. But most traits are the result of reinforcement in our minds, and perhaps bodies, hundreds or thousands of times over many years and it is no wonder that a similar prolonged intense effort would be required to change them. Alcoholics can testify to that.
Those conservative religious people who believe that part of their good news is that change for any trait is possible, though difficult, have solid scientific backing that it is not unreasonable to try. Is not potential change already the basis for political action of any stripe?
* Dr Neil Whitehead, of Lower Hutt, is the author of My Genes Made Me Do It!