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To pinky swear, or make a pinky promise, is the entwining of the little fingers "(pinkies)" of two people to signify that a promise has been made. It is often seen in anime, where it is called a yubikiri (指切り?, "finger cut-off"). The tradition also exists in China, primarily among children, where it is known as 勾小指 gou1 shou3 zhi3.
In the United States, the pinky swear has existed since at latest 1860, when Bartlett's Dictionary of Americanisms listed the following rhyme accompanying the promise:
The East Asian tradition presumably originates in China, thence spreading to Japan, and may be connected to the belief that soulmates are connected by a red string of fate attached to each of their pinkies.
In Japan, the pinky swear originally indicated that the person who breaks the promise must cut off their pinky finger.[dubious ] In modern times, pinky swearing is a more informal way of sealing a promise. It is most common among school-age children and close friends. The pinky swear signifies a promise that cannot be broken or counteracted by the crossing of fingers or other such trickery.