The researcher in that debunked study claiming gay parents raise worse-off kids than straight parents is now arguing it doesn't matter that he included only two stable same-sex households.

In a debate posted on Slate, which was among the first to let researcher Mark Regnerus air his claims in a lengthy article, he defends his study for failing to find more than two cases of children from a household "in which mom and her partner were together for 18 years."

Instead Regnerus says he relied on households that "appear to have witnessed midstream the formation of parental same-sex relationships. Given that age 14 was the year in which the most respondents -- 20 cases total -- reported living with mom and her partner, it suggests there are more of the latter than the former. Whether that matters for child outcomes or not is unclear, but may be challenging to discern due to small sample size."

Nevertheless, he decided to compare the kids who didn't grow up in a home with two moms to families that always had both a mother and father. And from that, he concludes, "the intact, biological family remains the safest bet."

Arguing the other side of the debate is Slate's William Saletan.

"The 'lesbian mother' group actually consisted mostly of kids who, by your account, had spent less than 'a good share of a year or more' living with a mom and her lesbian partner," Saletan points out. "The most common age at which kids reported living with a mom and her partner was 14, so it's unclear what kind of family structure these kids grew up in from birth to age 13. As you note, the two cases in which you found same-sex couples that stayed together for all 18 years of the child's upbringing weren't enough to generate statistically valid comparisons. To the extent that you found a pattern among the six kids who had lived with a mom and her lesbian partner for at least 13 years, the pattern was that those kids 'fared better on more outcomes than did their less-stable peers.'"