Jonnie Robinson, lead curator of sociolinguistics at the British Library, suggested to me that emoji shares some features with pidgin languages. Pidgins develop when two or more groups of people who don’t speak the same language have to find a way to communicate—on slave plantations, for example, where slaves from different parts of Africa would be working together. Pidgins typically have a limited vocabulary and lack nuance, a developed syntax, and the ability to convey register, i.e. to address your boss more formally than you would a friend.
Pidgin speakers, like emoji users, develop certain tactics to get around the constraints of their limited communication system, such as repeating a word to signify intensification: “big big” to mean “very big.” This is something which translates easily to emoji. Earlier this year Hogan, who monitors emoji use on Twitter, observed Justin Bieber fans tweeting rows of weeping emojis to signify their intense distress at his arrest.