A very important new study [1] that compares children raised in families headed by same-sex parents for part of 
their lives with children raised in other families was published this week.
The study has been heavily criticised [2] by advocates of same-sex marriage but the criticisms they are levelling at it apply with much more force to studies they quote in favour of same-sex marriage and parenting.
In other words, by attacking this new study by sociologist Mark Regnerus they are sawing off the branch on which they are sitting.
Or to put it another way, if we must disregard the Regnerus study, we must certainly disregard all the studies purporting to show that children raised by same-sex parents do at least as well as children raised by opposite-sex parents.
The Regnerus study looks at adults aged between 18 and 39 and the types of families they grew up in including step-families, lone-parent families, families headed by two married, biological parents, families headed by gay fathers or lesbian mothers.
The study is based on sound methodological standards and before the study was conducted, several experts ran the rule over the methodology and approved it.
It looks at the lives of 3,000 young adults raised in the various types of families and it finds very big, stark and detrimental differences between the lives of many adults raised in families headed by same-sex parents for some part of their childhood, and adults raised throughout their childhood by their two biological parents.
Critics of the study have been quick to point out that the study appears to be showing not the detrimental effects of being raised by same-sex parents, but the detrimental effects of suffering family instability during childhood.
No doubt they are on to something and Regnerus himself has been very careful not to make grandiose claims about his study.
Indeed, probably the one thing we can conclude from the study is that in the period under review there was a very high degree of instability in the relationships of gay and lesbian people.
Same-sex marriage advocates have said this is an argument in favour of their stance because marriage would add stability to their relationships.
But as this article [3] points out, same-sex marriage doesn’t seem to be providing this stability to same-sex couples. In countries that have had same-sex marriage or civil partnerships for ten years or more, same-sex relationships are still more unstable than opposite-sex relationships.
However, one thing that cannot be denied about the Regnerus study is that it is based on a random sample. The vast majority of studies to date into the effects of same-sex parenting have been based on very small, non-random, self-selected samples.
This is one reason why the criticisms directed by the Regnerus study apply with vastly more force to studies that back same-sex parenting.
Those who see the speck in the Regnerus study are very slow to see the beam sticking out of the studies they are fond of citing.
In a similar vein, those who point out that the money which made the Regnerus study possible came from conservative sources, or that Regnerus is a conservative himself, are very slow to point out that their studies are also funded by sources with a point of view or are conducted by scholars who are pro-gay marriage.
Of course, whatever the funding source, or the viewpoint of the researcher, what’s important is to look at the methodology and the quality of the research.
In terms of all the studies to date, the bottom line appears to be this; we don’t yet know in any definitive way what the effects of same-sex parenting are on children. Until we do, we shouldn’t even think about redefining marriage.
In this debate, the burden of proof rest emphatically on those who make the very radical claim that having a mother and a father confers no added benefits on children and that the natural ties don’t matter at all.
Same-sex marriage advocates have not even come close to meeting this burden of proof yet and it will be years before anyone is in a position to come up with large random samples children raised by same-sex parents.
PS. Here is another article [4] on the Regnerus study that is worth a read. And another one [5].
PPS.This is a nice, dispassionate article [6] (by New York Times’ standards) on the study. It acknowledges that the methodology employed in the study was sound. It also quotes pro-gay scholar (par 6), Judith Stacey, saying, “What we really need in this field is for strong skeptics to study gay, stable parents and compare them directly to a similar group of heterosexual, stable parents.”
We don’t have that study yet.