There have been studies showing that physical play with kids stimulates the release of beneficial brain chemicals.
Last week I was fortunate to have a lot of play time with a 4 year old boy which was much different than play time with a 4 year old girl. But they both seemed to benefit and enjoy what we called "wrestle time", or as they liked to say "wrastle".
The boy and girl were clearly different in how they spent this wrestle time. The boy appeared to want to test the limits and the girl in pinning me and getting pinned back.
What is clear to me that the time I give my girls for roughhousing would be inadequate for a boy - if I had a boy I'd want to dedicate periods of time where he could have physical play (with rules to keep it from being violent) and get out his aggression with the understanding that outside of "wrestle time" physical play was not appropriate.
And so it seems like fortuitous timing when returning to civilization I came across this in the news. Via MSNBC: Bring it: Boys may benefit from aggressive play