Amusing biographical note from
Sewall Wright and Evolutionary Biology:
...After Wright had clarified in the early 1920s the calculation of the degree of inbreeding in sexually breeding organisms, he calculated his own inbreeding coefficient. It was 6.3%, about one hundred times the average.
His parents were 1) first cousins and 2) Wright was descended from the Puritan stock of New England, so his genealogy was a tangle.