Parents tell me horror stories of hours of homework in third grade, of fighting their children to get it done when they are already exhausted from school and a myriad of structured activities, of it taking three times as long because the children just can't handle anymore work or structure.
Are these kids in public, private or charter schools? My experience around here is that private schools
tend to pile on homework and public schools don't. Example: the private school two of my kids attend makes it a point to say, "We have a low homework load." My kids (3rd/4th grades) have 45-60 minutes of work a night, four nights a week, and it's banned on weekends and over vacations. I know parents who chose this school to escape homework burdens at other local private schools. One school advertises 90-120 minutes of homework a night, starting in 6th grade, with projects over vacations.
Then there's the high-prestige prep school that gives 2-4 hours every night in high school and is described as a competitive pressure cooker.
Public school parents I know complain about how little their kids get ("He's in 8th grade and gets it all done during lunch, and he gets good grades.")
I've met a lot of private and public school kids around here who go to school, then go to an academic after-school program, and then go to music (or whatever) lessons. These kids eat dinner in the car. They're the extremes, but I know many kids with scheduled activities every day, Monday-Friday. I know kids (early elementary!) who have three scheduled activities every weekend (in addition to something like church). We meet them at birthday parties. They arrive late in dance/gymnastics/soccer etc. clothes and leave early.
There are also kids who don't have these demands on their time, but I've met too many ultra-busy kids to call them outliers. I can definitely see that being overscheduled could make them behave in ways the OP described. I can also see that the focus on test prep in schools could have that effect too.
