It's not entirely clear what the purpose of the philtrum — the indentation above the upper lip in humans — is besides allowing for a greater range of lip motions. There is a lot of legendary speculation on the philtrum's purpose, though. The ancient Greeks thought the philtrum was connected with love. In fact, "philtrum" comes from philtron in ancient Greek, which means "love charm," or "kiss." Ancient Greeks also considered it to be one of the body's most arousing places. In Jewish mythology, the philtrum comes from an angel putting its finger over the mouth of a baby to shush it to make it forget its heavenly knowledge.
More facts about philtrums:
- A smooth or flat philtrum may be a sign of fetal alcohol syndrome.
- Humans aren't the only ones that have philtrums. Most mammals, including dogs and many primates have a philtrum too.
- The length and shape of the philtrum in humans is genetically determined. If the philtrum does not form properly, a child can have a cleft lip or hare lip.