The word “testify” shares roots with the word “testicles”; why is it so you ask?
In ancient Rome, men swearing to the truthfulness of a claim used to hold their testicles while at it; two men taking the oath of alliance held each other’s testicles as a sign and a promise.
Sounds weird? Not really. Many other primates do it too; baboons for example hold each other’s testicles when they agree to cooperate against another baboon or a group of other baboons.
