One friend says he does find the thumbs-up cold and dismissive, but only when others use it and not him. Somehow, this makes perfect sense. Communicating via emoji is most fraught in a workplace.

For years, the thumbs-up sign has been the national symbol for “don’t worry, be happy.” With a thumbs-up man in the White House, the gesture seems to be getting more play than ever.

The thumbs up, the "OK" sign, and crossing your fingers are all examples of gestures that are vulgar in certain places outside the US. Not every hand gesture is universal.