Hey, look, guys, the subject is recoil and an 8-year-old kid. Noise is a health factor, also--which is why I'd disapprove of the use of a muzzle brake for a youngun's hunting gun.
The noise factor is true not only for 8 year olds, but for anybody. That's one reason I avoid excessive muzzle blast. I grew up in the 60's and 70's when hearing protection was at best an option, or not even thought of. Anything from cherry bombs, muzzle blast, to Top fuel dragsters (and loud music) has diminished my hearing to 2/3 of my original hearing, and I can't get it back without hearing aids, which I have opted out from so far. My advise is to wear protection religiously at the range, and avoid muzzle breaks or guns with loud muzzle blast at all costs. I prefer 24" barrels over 20" for this reason. I wanna protect what I have left.