I have African geese now, and I love them. They don't show any signs of aggression (unless sitting on eggs). Back when my kids were preteen, I had some mixed breed geese, and they were aggressive! But even then, they didn't go out of their way to attack, they just stood their ground where they were. Found out MUCH later that the kids teased the geese, and rode at them on bicycles to get the geese to chase. The kids weren't afraid of them. But I don't think that young children should be unsupervised around ANY poultry (I was at work and DH was home when the kids were teasing my geese and doing other things that are turning my hair gray now that I am finding out). Sebastopols are very friendly, they are common in petting zoos. They are also usually very expensive (hatcheries list for about $30 each), if you are just starting with geese you may want to start with something less expensive while you learn.