Authors:

From my experience working with comedians, there is that competitive aspect. With actors, for instance, they don't want to look competitive even if they are, whereas comedians, I think, are openly happy to play on the idea that they all compete with each other to get the laughs. There's something about comedy, I think, that encourages that. There's this kind of schoolboy sense of wanting to top the other person that we play off of to show them competing for who's smarter or cleverer.

Source: www.avclub.com
From my experience working with comedians, there is that competitive aspect. With actors, for instance, they don't want to look competitive even if they are, whereas comedians, I think, are openly happy to play on the