The full text of the study is behind a paywall [1], but from the abstract we can see that:

- It's 47 participants (out of 69 recruited)

- The only other variables controlled for are household income and age

The study's conclusion itself says:

> The findings suggest further study is needed, particularly during the rapid early stages of brain development.

So we should all be interested in the results of that future study, but at this point nobody can really make a strong claim one way or the other.

1: https://jamanetwork.com/journals/jamapediatrics/article-abst...