In the western context they evolved from the attempt to convey emotion in text form. Writing systems are mostly meant to convey facts, while the emotion that we encode in intonation is completely lost. That lead to problems in pure text communication, so we invented emotes to convey the difference between
"It was a very sunny day :)"
"It was a very sunny day :\"
"It was a very sunny day ;)"
Some web forums started replacing them with images which lead to designers inventing more emojis, and due to Japanese carriers wanting the same for SMS those got incorporated in character encodings.
What seems strange to me is that most emoji that exist are completely useless for the purpose of conveying emotion, or encoding any useful information that can't be expressed in a word. It's like some designer had to fulfill a quota or someone wanted to just "have more emojis". Yet the most popular emojis are clearly still used to convey emotion [1].
"It was a very sunny day :)"
"It was a very sunny day :\"
"It was a very sunny day ;)"
Some web forums started replacing them with images which lead to designers inventing more emojis, and due to Japanese carriers wanting the same for SMS those got incorporated in character encodings.
What seems strange to me is that most emoji that exist are completely useless for the purpose of conveying emotion, or encoding any useful information that can't be expressed in a word. It's like some designer had to fulfill a quota or someone wanted to just "have more emojis". Yet the most popular emojis are clearly still used to convey emotion [1].
1: https://emojipedia.org/stats/