Ruffalo told Access Hollywood that his 10-year-old's tantrums gave him some ideas about how to play the famous character.
"I was channelling my 10-year-old son, who I dedicate my performance to," he said.
"It's that horrible moment in a child's life when the world expects a certain kind of behaviour from [them], but [they] can't quite hold it together and [they] break out in rage and it's Hulk-like. So I used him quite a bit for that character."
Ruffalo has previously admitted that seeing himself as a Hulk "scared the hell" out of him and joked that it reminded him of his father when he was "really mad".
Ruffalo has also revealed that he would "love" to star in a Hulk movie and has said that Bruce Banner would be a nice addition to Iron Man 3.
The Avengers opens in US cinemas on May 4, and in the UK as Marvel Avengers Assemble on April 26.
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