I think I've come across this a couple of times. My son is only 5 so anything could happen, these children that I think are a bit too wild may not be in a yr or 2.... like the article says, at that age the child could grow out of it.
But you know, when you just know that that child will be a bad influence even in 10yrs time. You can sort of just tell.
My son is no angel, but he is empathetic. We are bringing him up to be respectful to people and their feelings, just like we are with him. He has his moments of wildness, and although we have yet to meet another child friend of his to be purposefully mean or horrid, I have met children who just seem to have something about them which means they are okay now, but I reckon they'll be a bad influence in a few yrs time.