At Waffle House, if the staff see you fighting in the parking lot, they come out and yell at you to “take it inside”.

“85 to 90 per cent of cousin couples do not have affected children”

So imagine 10 couples: 1 couple has an affected child, the other 9 couples do not have any children. In this case, 90 percent of couples do not have affected children but 100 percent of children are affected. I wonder why they presented the statistics using that particular, odd means of phrasing.