This is simply not the case. That is the primary purpose and intent of applause but not necessarily the only one.Clapping is done for the benefit of the artist or performer, whom are not present at a typical movie screening. Unless you're clapping for the projectionist, I don't understand why you would do it. It's obviously a cultural difference.
As Karkador pointed out: ever cheered while watching a sporting event on TV with friends?Welp I catching up with this thread and about to post this. I have never witnessed anybody clapping at the movies. Do you guys clap at home after watching a tv movie? After the 8 o'clock news perhaps?