That was not at all as conclusive as I was expecting, for several reasons:

* it's study not studies

* it refers strictly to educational performance

* it's likely detecting something else entirely: "The researchers found that same-sex parents are often wealthier, older and more educated than the typical different-sex couple. Same-sex couples often have to use expensive fertility treatments to have a child, meaning they are very motivated to become parents and tend to have a high level of wealth. This is likely to be a key reason their children perform well in school, the economists found" [...] "When the economists controlled for income and wealth, there were a much smaller gap between the test scores of children of same-sex parents and children different-sex parents, although children of homosexual couples still had slightly higher scores."

Regarding the third point the conclusion still supports what I said, that there's no big gap.

A basic google query will get a ton of results. Here are a few.

Overview of 75 studies: https://whatweknow.inequality.cornell.edu/topics/lgbt-equali...

https://thinkprogress.org/same-sex-parenting-study-age-25-67...

https://qz.com/1320434/new-research-debunks-old-science-abou...

This has turned into a time sink with no upside for me. I've looked at some of the articles you posted which are pretty low quality. They seem more concerned about winning some USA-only political points than discussing the topic in an objective manner.

If you're making the effort of linking to studies that support a specific statement, please link to the actual studies and not opinion articles about them.

In any case, I would not expect kids with same sex parents to do worse in school or have noticeable psychological issues, which is what these studies were looking for - these are pretty heavy issues after all.

But I would expect that they are slightly worse for subtler reasons: maybe they're a bit more prone to infections in the first years because they weren't breast-fed, maybe they're distressed in school because they're being subtly bullied (mentioned in one article, btw) and so on. Remember that the original claim was "they're no worse", not that they're not much worse. I agree that they're probably not much worse, but a male-female couple has thousands and thousands of years of social support and nature on its side. Of course it's going to be in some ways better.