Whedon explained, "The Avengers
was the most ego-free set that I can remember being on. They were all in it to play, to help each other, they were having a great time, there was a lot of trust. That's something one works hard at."
He added, "In the case of The Avengers I was lucky because a lot of the movie had been cast before I came along, obviously they already had their own movies. Some people said, 'Well, it's going to be an egofest'. I said, 'No, I think these people are actually going to be looking out for each other'. And they really were."
The Avengers is set to be released in the UK on April 27 and in the US on May 4.