“Aggression is not seen more frequently in 47,XYY males.”
https://en.m.wikipedia.org/wiki/XYY_syndrome
What does this mean?
Means you can have them over to dinner and not worry about your wife and kids. They are normal in every sense of being a man just more so. I would bet 1/3 of Pro athletes are XYY. Fro boy is more likely XXY.