The Disturbing Origins of the Pinky Promise

I think every single one of us at some point in our lives has made a pinky promise, whether it’s keeping a secret between childhood friends or making some form of commitment. The pinky promise is the ultimate gesture of keeping a sacred vow.

Locking fingers and reciting a rhyme like a binding spell carries more weight than a simple promise. I remember making pinky promises as a child, and people would say,

“If you break the promise, I’ll break your finger”.

The very prospect of someone breaking my pinky definitely ensured I kept the promise. But where does it come from? Who started the idea of the pinky promise? And most of all, for something that appears so innocent, simple and childish, why are the consequences so violent?

Yubikiri Genman

In 17th-century Japan, the pinky promise was conceptualised. This, however, was more gruesome than our modern alternative. People, mainly courtesans, would cut off the tip of their pinky to give to their lovers. It was seen as the ultimate display of utter devotion. This was known as Yubikiri, and was accompanied by a threatening song.

“Pinky swear,

whoever lies will be made to swallow a thousand needles,

punched 10,000 times and fisted 1000 times.”

I’ll give you a moment to take that in…

What I find most interesting about the rhyme boils down to the era in which it was conceived. The Yubikiri originated in the early 1600’s around the beginning of the Edo Dynasty.

After years of bloodshed, the Edo period was said to be peaceful and stable; by all accounts, a functional, secure isolationist era. It was considered so peaceful that the Age of Samurai faded into irrelevance.

And yet, even in times of peace, courtesans were cutting the tips of their pinkies as a grand loving gesture.

Merchants also did well in the Edo era, even trading with European countries despite its isolationist policies. This must be how the pinky promise spread across continents. Morphing and changing along the way.

The Songs

In England, particularly the Isle of Man, we would lock our pinkies, shaking our hands up and down, reciting:

“Make friends, make friends,

Never ever break friends,

If you do,

You'll catch the flu,

And that will be the end of you!”

I suppose compared to the Yubikiri Genman this one is kinder? I guess? At least you get to sing along melodically? That’s the cheerful bit, right? Thankfully, there is no finger cutting here.

Obviously the ‘flu’ refers to the plague, similarly to the nursery rhyme ring-a-ring-a-roses. The UK and Europe have a long history with the plague. 17th-century England had many spikes of plague outbreaks, particularly in 1665. A lot of the UK’s quirky customs have their roots in the plague, like how we say ‘bless you’ after someone sneezes.

Trade in Japan ended with the Edo dynasty in 1635, but the pinky ritual had already spread across borders. Just as Europe began expanding theirs…

In North America, towards the end of the slave trade, the pinky swear sprouted, and another song of a similar nature was made. Instead of the plague, it was ships.

“Pinky, pinky, bow-bell,

Whoever tells a lie

Will sink down to the bad place,

And never rise up again.”

The act of breaking a vow remains the same no matter the location. Each variant of the song, however, becomes geographical as it weaves the traumatic past of each country, slowly embedding itself in culture over time.

This makes the weight of the unbreakable vow even heavier than it appears. These aren’t just words that rhyme. It’s not just an informal sealing of a precious agreement; it’s carrying a memory.

A Global Ritual

In modern-day South Korea, the pinky promise ritual is accompanied by a seal. The thumbs of each participant press up against the other, while each pinky is still hooked.

In Russia, locking pinkies is a symbol of peace; it is usually done after a row. Even if the participants argue in the future, the pinky promise ensures they remain friends.

There are many different versions of a pinky promise across continents. All slightly different from each other, with different names and practices. Ultimately, the act is an agreement, a vow, an oath, a promise. The consequences, though unlikely to occur, are violent in nature and infuse a past that refuses to be forgotten.

Thanks to our 17th-century and 18th-century predecessors, we have the pinky promise as we know it today. Carried across the seas just like the plague and colonialism, one place at a time.

Today’s pinky promise is less about physical violence and more about a literal warning. It is a present act with its roots firmly in the past, refusing to be left behind.

Originally posted to Substack.