Edvard Westermarck
Edvard Alexander Westermarck (November 20, 1862 - September 3, 1939) was a Finnish philosopher and sociologist. Among other subjects, he studied exogamy and the incest taboo.
He is known for first noting the Westermarck effect in which infants raised together are unable to form sexual feelings for one another as adults, regardless of their genetic relationship.