Of the six billion emoji that are sent globally every day, around 70% are emotion based – for example, smiley face, love hearts. A smaller proportion of the emoji sent are sad expressions.

Smiley-face emoji, at least, might alleviate some of that aggravation, especially in settings where the waitstaff or service workers deserve a little extra, Lefebvre and her co-authors suggest.

Emojipedia will give you a brief description of that emoji. For example, here's what Emojipedia writes about the " ‍ ️" (face in clouds) emoji: "A face that appears surrounded by ...

In the early days of online chatting people used different characters on the keyboard as a shortcut to convey an emotion. The happy face :) to convey happiness or joy. The frowny face :( to convey ...