Several friends asked us if twins run in our family. The answer is: yes... but only on the paternal side. The tendency for twins is passed on through the maternal line only so the fact that we're having twins is pure chance.

Nevertheless, it's fun to look into our family history. My greatgrandfather Johan Jacob was born in 1891 in Egmond aan Zee, the Netherlands. He and his brother Marinus were twins. Johan Jacob's son Gerrit married Johanna. Their first child was my father. Four years later my grandmother learned that she had carried twins only when she gave birth! One of the twins, my aunt Ria, later gave birth to my dear cousins -- again, including twins.

Through my uncle Harm I recently got in touch with descendants of my grandfather's brother Joop. Three of my second cousins had twins also.

Like I said, it's highly unlikely that there is a biological reason for this but it is fun to find out about other twins in the extended family.