Yes, so long as it's based on a child's ability. Different students are at different places in the classroom, and while it's noble to catch those falling behind up, we shouldn't limit what we teach the kids that are further ahead. Otherwise we only encourage and endorse mediocrity instead of giving the kids that need it extra challenges so they'll still be engaged and enjoy learning.
Yes lets overload a child's small brain with so much information that they fall over into a coma.
Come on now. The great purpose of teaching comes from layers.
You start out with the basics of math, history, English and so on, and then you repeat what you learn the next year and add more info. This repetitive teaching has been proven to work for thousands of years.
Of course information is restricted they have no foundation to base the information off of. Thus you start out nice and simple and work your way up.
How the hell can you teach a 6 year old quantum mechanics, sex ed, and Neopolean conquests in the same year?
For instance, under no circumstances should a six year old have to know about puberty. Should schooling attempt to teach a bit of algebra? Sure! I taught my younger brother about algebra when they were 7. The schooling system is pathetically slow on it's students. It was easy to get 2 or 3 years ahead. Finally at secondary school, they are actually putting up decent challenges for me. But if primary had stretched me, I'd be much, much smarter than I am now. So without many restrictions, yes. Without all, unfortunately, no.