When, who and why did we start clapping to show appreciation?

clap emoji

Question:
When, who and why did we start clapping to show appreciation?
Mary, Howmouth 

Answer:
*Definitive*
Name: Rebecca, Carshalton
Answer: It’s from ancient Greece when people use to impart their knowledge to large rooms of people. At the end of the speeches people would come up and slap them the person on the back to say thank you, people who couldn’t reach the person who was talking would put their hands together.