The definitive study of this subject (in terms of citations, over 500), is Patterson, Child Development 63:5, 1025 (1992), and finds that, “to date … there is no evidence that the development of children with lesbian or gay parents is compromised in any significant respect relative to that among children of heterosexual parents in otherwise comparable circumstances.” This study addresses the results of other studies.
In my opinion, all of these results so far, on either side, can be explained by statistical fluctuations, given the very small sample-size, and inability to correct well for extra variables. Anyway, what this means is that we can consider any publication before 1992 as having failed to provide good evidence of a difference in development.
So we look at the articles after this point. Current research shows incest and abuse issues with gay couples to be either the result of problems with the data, or in the case of non-biological parenting, a risk that is not significantly higher than the same risk heterosexual non-biological parenting imposes on a child.
This leaves P. Cameron and K. Cameron, Psychological Reports 82 (1998) 1155. This article has been cited only 16 times, includes a very small sample, and is in my opinion a statistical fluctuation. Despite Cameron’s own stake in this issue, I will give him the benefit of the doubt, and will assume he performed his research honestly and with carefully chosen population samples.
Why do I think this is a statistical anomoly, and simple data-interpretation? Because researchers who have stake in the other side of the issue (Bos, Balen, van den Boom American Journal of Orthopsychiatry, 77:1, 38, 2007) had this to say, based on the exact same available data, and different statistical samplings and analysis:
“With regard to parental characteristics, there is an agreement in empirical studies that there are some differences between lesbian parents and heterosexual families. Evidence suggests, for example, that social mothers (nonbiological mothers) spend significantly more time performing family and childcare activities than do heterosexual fathers. Lesbian couples share household tasks more equally than heterosexual couples do (Patterson, 2002). The fact that the division of family tasks and childcare activities seems to be more equal in lesbian-parent families (Brewaeys et al., 1997; Patterson, Sutfin, & Fulcher, 2004) might be the reason why lesbian parents are more satisfied with their partner as a coparent. It was also found that lesbian and heterosexual-parent families differ as regards the intensity of the desire to have children, with lesbian parents having a much stronger desire (Bos, van Balen, & van den Boom, 2003).”
It’s a completely different result!
So the best conclusion I can reach is that I don’t want to make a conclusion. There’s no good evidence that gay couples provide a better or worse environment for children than straight couples at this time.
When there is good conclusive data, I’ll base my position about gay adoption on that data.