Lulu, I was about to say a similar thing. Boy's are far more likely to see other boy's penises while at school in the toilet etc then they are their father. So they are more likely to be different to most of their peers.

You have to remember that when our partners were infants circumcision was almost a norm. So pretty much most of the men around late 20's, 30's even 40's are circumcised, and their children are mostly not.