One thing which has struck me about the Kennedy clan is that it seems inordinately fecund. The GSS tells me that in the 2000s white non-Hispanic liberals who are over the age of 45 have on average fewer than 2 children each. The ideal family size for the same segment is given as a little under 3. There isn’t any significant difference when constraining to the subset to those who are Roman Catholic.

So is my intuition about the Kennedy clan correct? There’s a helpful Wikipedia page which lists the descendants of Joseph P. Kennedy and Rose Fitzgerald Kennedy. Several of their children died too early to have any children of their own, or did not have children. Nevertheless, I count 69 great-grandchildren of Joseph P. Kennedy! Since his coefficient of relatedness to his great-grandchildren is 1/8, you get 8.63 in terms of his contribution to the current generation. But the real action is in two of Joseph P. Kennedy’s children, Eunice and Robert, whose own children seem to be quite prolific themselves. Below the fold is a list of the descendants. I’ve omitted some of those with no children in the first two generations.