I wouldn't worry too much about it. My son is 1, and he's been doing the same thing for about a month now. He's in daycare, and according to his teachers, this is a completely normal phase, especially for boys. Unfortunately, even at your son's age, there's not a whole lot you can do discipline-wise. I've been instructed to first, make sure we don't "rough house" at home, like, letting him tackle us, wrestle w/ him, etc. Then, just remove him from the situation and distract him w/ something else. I've learned you really can't even teach them "gentle" -- by words or demonstration -- until they're older toddlers. It's a tough stage, but I assure you this is totally normal behavior. And I think you hit the nail right on the head w/ the "curiousity" thing. That must play a huge part in it. Our son has been less aggressive the past week or two, w/ some "bad" days here and there. But remember -- your son is NOT intentionally trying to hurt other kids, and he has no idea that what he's doing isn't perfectly normal and fun, so don't be too harsh w/ the discipline. I think that might just scare him. It sounds like your little "time out" isn't too harsh -- just speaking in general. I think our son's teachers usually put him in his crib for a bit -- just remove him from the situation and let him play by himself, "contained" (ha ha), for a while. Good luck!