Unfortunately, I wasn't able to find out much about the history of applause other than the fact that we have evidence for clapping as early as the 3rd century B.C. in the Roman Empire. I suppose the action just originated because it's easy to do and it's pretty loud. I'd like to find out how many lone souls it takes to start a room full of applause and how many people have to discontinue the action for the clapping to die down. To save myself from making an entire works cited page for this blog, however, I'm going to opt out of researching these questions tonight. I do know, however, that an audience's applause can tell a speaker A LOT about how the congregation is receiving his/her message.
I gave a couple of speeches at the end of my senior year of high school, and I found that being interrupted by sporadic bursts of applause is the best feeling in the world. In regards to public speaking, we clap to show that we agree with what the speaker is saying, and the energy of the applause displays the level of our approval. If an audience gives a weak, half-hearted clap, it is clear they were disengaged or unhappy with the message delivered. If a hearty applause at the end of a speech is heard, it is safe to say that the dialogue has been well accepted. Sometimes, we simply go through the motions of clapping when the timing is right, and the applause means nothing at all. It is when a rhetor speaks with passion about his cause that excited clapping, screaming, whooping, and whistling interjects before the oration is over, and such applause motivates the speaker to continue with even more animation than before.
Public speaking is an excellent means of rhetoric if you want to experience the reactions of your audience firsthand. When we hide behind text, we are spared from realizing that our message didn't get the approval we hoped for, but we also miss out on the rush of excitement when a room fills with applause at your words.
http://www.google.com/imgres?q=clapping+hands&hl=en&biw=1440&bih=838&gbv=2&tbm=isch&tbnid=McIaW7iy15VFvM:&imgrefurl=http://medicmagic.net/clapping-hand-can-increase-childs-intelligence.html&docid=gjQJ3eX4HBtzCM&imgurl=http://medicmagic.net/wp-content/uploads/2010/05/children-clapping-hands.jpg&w=506&h=337&ei=AzIiT4vyM8Ph0QHa4f3nCA&zoom=1&iact=hc&vpx=414&vpy=410&dur=368&hovh=159&hovw=210&tx=176&ty=95&sig=109290321251259403933&page=2&tbnh=157&tbnw=206&start=32&ndsp=34&ved=1t:429,r:28,s:32
References
http://www.esquire.com/style/answer-fella/history-of-applause-0209