Families with twins.

Across the full Sassano-Bompietro tree — now 25,587 individuals and 6,589 families as new records keep getting added — though this particular update left every twin statistic on this page completely unchanged — 289 sets of twins, and one set of triplets, are documented between 1671 and 1971, identified by siblings sharing an identical birth date. That's roughly one twin-birth family for every twenty-two families in the tree overall — still a little above the general historical rate of twinning, without being so far above it that the pattern speaks for itself. It needed a closer look.

The more interesting question isn't how many twin births there were, but whether twinning tends to run in particular families across generations, rather than appearing once and fading out. To get at that, every twin's own descendants were traced forward, generation by generation, checking whether any of them turned out to be a twin too. That search turned up 34 family lines where twins were born again later — one more than last update.

Seven separate cases remain the closest recurrence in the tree, all exactly one generation apart: Giovanni di Sisti & Antonia Apollonia Calandriello (1707→1749); Giovanni Florendino & Perna Apollonia Belleza (1701→1748); Cesare Matteo Feminella & Antonia Zozzaro (1720→1763); Paolo Biancamano & Agnese Caputo (1824→1856); Giovanni Libretti & Maria Spina (1833→1881); Agnese Petrizzo, herself a twin, who had twins with Giovanni Maria Benvenga; and Giuseppe d'Amato, a twin born to Dario d'Amato & Albabella Florendino, who later had twins with Arcangela Pellegrino. Seven families showing the same direct, one-generation pattern remains a considerably stronger signal than a handful of isolated cases could offer. The rest of the 34 recurring lines stretch further — three, four, even six generations between one twin birth and the next in the same family line, which is exactly what you'd expect once a family has spread into enough branches that a repeat becomes statistically likely again on its own, hereditary tendency or not.

By sheer volume, the leaderboard has a new co-leader: Feminella climbed to 12 twin-birth families, tying Carlo at the top for the first time. Di Luca follows close behind at 11, ahead of a three-way tie at 9 — Libretti, di Miele, and Petrizzo.