Humping other male dogs

My 10 month old male is bad for trying to hump other male dogs in between pretending to play with them! He's not neutered and I may or may not get it done in the future.
I was just wondering if anyone knew what the reasons for it were? Some people have suggested it's a dominance thing. Is that the generally accepted reason for this behaviour?

i have never had a male but yes it could be a dominance thing.

In my experience with Vin I put it down to a dominance thing,it just needs to be distracted straight away.

I also think its dominance thing

I've never had a male either but would agree with the above posts.

If it's during play I'd be inclined to go with over excitement/excess energy that he's not sure to do with - my girl is anxious around other dogs and humps in play or when she gets too excited to see humans! Distract and give a small break from play when he does it, many dogs won't tolerate. Neutering would probably help - but then, my spayed female humps so it's not always a testosterone thing.