Same goes for your kid. It may be encased in a remarkably strong skull, but the neurons inside need to be treated with respect. Tackle football in middle school, not to mention younger, with its hits and slams and sometimes concussions, doesn't show that brain respect. Neither does tackle football in high school, college, or beyond, but the older brain is a little different and the research not yet as crystal clear. At least according to some… I still worry about those brains of older kids' big time.
I am not suggesting that you push your child to live life in a bubble because that's just as debilitating in an entirely different way. But enrolling him in any activity that causes repeated high-impact head bonks can lead to chronic injury inside the brain, often invisible for years until one day it's not. This is the story of CTE. We cannot ignore it, overlook it, deny it anymore. So this is what you must weigh as you decide whether your son (because it's almost always sons) should play tackle football and if he will, then starting when. And since we, as parents, ultimately sign the forms and enroll our kids in one activity or another, driving them, cheering them on, it is on us to choose to be brain protectors.