"All he found is that family instability is bad for children and that's hardly groundbreaking or new," Gates, who was not involved in the research, told LiveScience.
"What I find most frustrating is that from what I could tell, he could have used his data to test the way I'm suggesting the test, and he chose not to," Gates added. "He intentionally chose a methodology that is absolutely primed to find bad outcomes in those kids."
Regnerus said he plans to look more closely at the experiences of the same-sex parented kids in an upcoming article.
"A detailed exploration of who lived with whom, when, for how long, etc., was not the point of this study," he said.
Where same-sex parenting stands
Regnerus detailed his findings Sunday (June 10) in the journal Social Science Research, alongside several commentaries on the work. The study was funded by two conservative-leaning foundations, Witherspoon Institute and the Bradley Foundation, though the funders had no control over the study design, interpretation or conclusions, Regnerus wrote.