[icecream_so_gud]

There are social pressures why a kid wouldn't want to move between tracks. All their friends are there.

They may also want to avoid moving to a higher track to avoid teasing from colleagues for being a "smarty-pants" or perceived as too good for the friend group.

[spywaregorilla]

anecdata of one, but I was pretty far ahead of my class early on and as a result, I learned to behave like an idiot as a way to gain social acceptance. This culminated in resentment and general failure to socialize properly. It wasn't until 11th/12th grade that it clicked with me that I really ought to stop expending so much energy trying to maintain early childhood relationships and should instead try to make better friendships with my peers in advanced classes.

"too good" is elitist language, but I was clearly differently minded from my peers in early grade school and I think it harmed a lot more than it helped.