Roughhousing: a conundrum

I grew up with two younger sisters and girl cousins. Until my son was born, there wasn't a boy child for an entire generation. Plus, my husband has two sisters and his sister has all girl children. We are just swarming with chicks in our family. Which is why I don't know anything about how boys play.

Of course, one cannot over-generalize. There is no one way that boys play, just as there is no one way girls play. The reason I know this is that my daughter is much more physically aggressive than her brother and likes bloody, spooky things even more than he does. Also, I've got a son who quotes Shakespeare. So I'm not putting anyone in boxes.

That said, I have noticed that when another little boy comes over to play, both the kids' first instinct is to make high-impact body contact with each other. The kids walk in the door, kick off their shoes and within a minute its WWW wrestling in my living room. I believe the official term for this activity is roughhousing. It is as foreign an activity to me as Mah Jong or wood whittling. I don't know how to do it and I don't know what's appealing about it to other people. But, unlike Mah Jong or wood whittling, which are perfectly pleasant pasttimes that do not harm anyone, roughhousing does, in fact, harm people. I don't mean that it has the potential to harm people. It ALWAYS does. inevitably. Sometimes it takes five minutes, sometimes half a minute and sometimes the kids can go almost 10 minutes without bonking heads or hurtling themselves into a nearby piece of furniture. But in the end, all roads lead to physical injury. What is pleasant or enjoyable about an activity where someone is guaranteed to be pained? I just cannot say.

But the real problem is that I don't really know how to respond to the roughhousing instinct.

Do I let the kids wrestle?
Do I forbid it?
Do I allow it, with parameters? If so, what the hell would those parameters be? The whole point of the roughhousing is to make contact, after all -- that much I can see. Its like a boy way of holding hands or hugging. It warms the cockles of their heart. It can't be simulated.

I am always left standing on the sidelines, ineffectually yelling "Be careful! Be careful! Oh hey, watch OUT!" or "OK, I think that;s enough! Let's stop before someone gets hurt!"

I mean, clearly its a consentual act, that both parties are delighted to engage in. Clearly, no one is being malicious or angry or bad-intentioned. And my instinct, as a parent, is as long as everyone's happy with the game and their heart's in the right place, well, let them do what they like. But then I wonder: do other parents allow the roughhousing on playdates? Is this DONE?
Of course, in a neighborhood where parents don't let their kids lick the spoon when baking cakes and boycott burger joints with TV screens in them, well, anything's possible.

Oh, males are so inscrutable. Which is funny, since they're so damn simple.