I loved learning about this phenomenon from Patrick Collision’s blog.
Anecdotally, this makes sense to me. Up until the 3rd grade my mother would work with me every single day on my homework. I was consistently number 1 or number 2 in my class.
This changed when my mother began spending more time with my siblings my homework than with mine. I personally believe simply having someone with you to walk you through problems makes all the differences in the world.