Are Large dogs more likely to start a pack and attack small children

You know, I've never really thought about this before, but yes, it does seem to be a problem with the larger dogs. I've seen some nasty little dogs that yip and bite, but they never seem to have the pack mentality. Out here in the countryside where I live, people often let their dogs run free. My one uncle had to give up his sheep farm because of packs of dogs. If you lose 2-3 sheep a day to them, it's not worth it! (They were all big dogs, shepherds, etc.) Interesting observation, you got me thinking! I think with rotts and pitts that it's an inbred trait for the most part. Part of it too, is how they are treated as a puppy. I have a large dog, but it is trained...if it was aggressive towards my grandson, I wouldn't even think of keeping it.