"Algebra seems to help [students], but it's not clear it's the curriculum. It's the peer environment. It's the teacher. It's just the pat on the back for being in an advanced class. All kinds of stuff is going on there, and we don't know which it is," says Domina. "Now, when you change that and put a lot of kids in algebra, you change the peer environment, you have teachers who have never taught algebra teaching algebra, and you've got this problem in the classroom where you've got to figure out whether you're going to teach algebra at all, because a bunch of the students don't know fractions." 

I do not understand this. The earlier you start with algebra, the easier it is.  Middle school is the best time to learn skills.

Yeah, I do not understand this either. 

Everyone needs algebra.