The high-throttle dialogue in The Social Network is, for me, a key reason why it works as well as it does. As I wrote last Monday night, David Fincher‘s film is like “His Girl Friday on Adderall.” It’s also spoken with the same rapidity that Ken Russell chose for 1980’s Altered States (a decision, incidentally, that so angered screenwriter Paddy Chayefsky he removed his name from the credits).

(l.) Social Network star Jesse Eisenberg, (r.) Facebook co-founder Mark Zuckerberg

The reason for the pacing of The Social Network, in any event, is explained in Mark Harris‘s New York article (“Inventing Facebook”) about the forthcoming Sony release.

“[Aaron] Sorkin‘s shooting script was 162 pages,” Harris writes. “Using normal one-page-equals-one-minute Hollywood calculus, [this] would have yielded a two-hour-and-42-minute film instead of the one Fincher made, which clocks in at a fleet two hours, not including closing credits.

“After Sony looked at the draft and told them they’d have to cut the script, [director David] Fincher says he and Sorkin went back to his office, ‘and I took out my iPhone and put the little stopwatch on and handed the script to Aaron and said, ‘Start reading.’ He was done in an hour and 59 minutes. I called the studio back and said, ‘No, we can do this. If we do it the way Aaron just spoke it, it’ll be two hours.’

“Sorkin’s and Fincher’s confidence was boosted when they watched Jesse Eisenberg’s audition. Eisenberg, 26, who has become, in The Squid and the Whale, Zombieland and Adventureland, something of a specialist in motor-mouthed, sharp-minded, neurotic young men, put himself on a QuickTime video reading a scene as Zuckerberg.

“Sorkin’s characters, says Fincher, ‘are people who need to work their way through the kelp beds of their own thought processes on their way to the exact idea they’ve been trying to find.’ And Eisenberg was ‘the first person who could do Sorkin better than Sorkin. He can just flat-out fly. You can see in his eyes that he’s searching for the best way to articulate something in the middle of articulating two other things.”

“Other actors, however, didn’t find those familiar rhythms until they were in the presence of the screenwriter. When Justin Timberlake, who plays an impish, diabolical version of Napster founder and early Facebook partner Sean Parker, auditioned, he read opposite Sorkin, who was playing the role of Zuckerberg.

“‘It was awesome,’ says Timberlake. ‘Aaron writes like he speaks, so when you say his words, you hear his voice in your head a little, dry and witty. And in the audition, when I heard him say his words, I thought, Oh, so that‘s how fast this screenplay of 100,000 pages is gonna go by!'”