Most people I know send the sassy ones to the auction barn!! They dont get a chance in H-E-double hockey sticks!
Like everyone else said, you will find hot heads (sassy) cattle in every single breed. Around here I have heard of everything from Maines, Saler, Charolais, Limo, and some Simmys. I dont think it is breed specific, and I have seen puppy dogs from all of those breeds. My sister has 100+ cows, and her son has grown up around them. Imagine a 3 year old walking through a pen of 40 yearling heifers. I was panicking watching him walk directly, and I mean DIRECTLY behind them brushing up against their bellies and legs. I was freaking out, but each and every one of the heifers was a total sweetheart. I think a lot of it has to do with imprinting as well...just like foals. Notise most bottle fed calves are annoying and wont leave you alone even when they get to be 1+ years old. Just spending a lot of time around your cattle, and walking through the pens will really help get them used to people. Animals tend to find children freaky...i guess cause they are miniature adults and are usually rowdy. If you want....as SAFELY as possible, get a couple of kids to walk around with you sometimes. But dont be like my sister (lol), unless you know forsure the animals are ok with the kids!!!! Make sure the kids are at your reach at all times so you could grab them or their hand if something ever does happen.
I have probably made it sound like I put kids in danger but come on everyone...use common sense here. If the animal is phsyco, lock the kids in the house.