There's a very different set of labor laws for those under 16, it's just not feasible most of the time to have someone on board who can only work certain hours, but no more than 4 a day, and has a mandatory break every 2 hour (varies by state).
Yeah that's similar to how it was when I started working. I was 14 and was only allowed to work 4 hours on weekdays even though my employer didn't care and let me work 6/7 hours.
