Hi,
A survey done in the late eighties in the U.K. showed that most dog bites were from Golden Retrievers, this sticks in my mind as I was working with Retrievers at the time and now own one. There was a factor that shouldn't be ignored - they were also the most popular pet dog at the time. Taking into account that there were more of this breed in the country than any other and therefore it was probable that more retrievers were owned by less than ideal owners than any other breed you have to wonder how significant the figures actually were. But (oh the inevitable but!) because demand for these dogs was high and there was money to be made breeding figures also went through the roof. Indiscriminate breeding of Retrievers is still ongoing, you only have to look in any local paper to see the ads. Given that people with no experience and knowledge were throwing out puppies ten to the dozen it is little wonder we have ended up with some pretty extreme animals.
On the plus side, you will tend to have a sound retriever that is 100% or a complete dominance freak that shows it's true colours early or a nervous shy dog that you have to watch like a hawk (this type can be rehabilitated sometimes). Obviously this is a very simplistic view of a far more complex subject but I think I'm saying too much too often at the moment!
As for a good dog around children - there are only good children around dogs! Greyhounds on the other hand tolerate almost hell and then they will look for somewhere else to lie rather than retaliate.