Just using the extremum to show there is a difference.

The difference is not limited to the extremes. Why would it be?

Hence spectrum.

And math meet people early in the spectrum.

EDIT: thread limit reached, so I can't answer down there.

But in short, it's a HN comment, not a study. But I've been in 11 schools in my life. Some private ones with their own church inside, some for special kids, some for poor kids with a higher degree of violence.

I saw it again and again. The average math teacher is not worse than any other teachers. But the first field kids have a hard time is more often math than other fields. In fact, kids that are good at math usually can do ok in any other, even if not great. The reverse is not necessarily true.

At this point I'm just repeating the argument in the other comments.