Is the opening break-up scene in The Social Network intended to be humorous?

Having inside-depth knowledge nor references, I do not think the opening scene is intended to be humorous. To my opinion, the opening sequence serves foremost as an introduction to Mark's character and his intelligence, but at secondary level as a preview to the audience to what is be expected, namely the rapid pace of conversation and mind-switching. It is saying: "Pay attention!"

Some people label parts of it as being humorous, but that is just individual taste. This scene's calling up of different emotions is evidence of Aaron Sorkin's superb writing.

I do think the scene is intended to be humorous. Not only humorous - its real purpose is to give us a brilliantly succinct introduction into Mark, his personality and the factors that motivate him throughout the rest of the film - but it's definitely funny for two main reasons:

1. There are just some flat-out funny lines, like when Erica tells Mark "[I can't talk any more] because it is exhausting! Dating you is like dating a StairMaster!"

2. We're amused by people who are rude without realising it. Look at comedies like Fawlty Towers and The Office: almost all of the humour comes from a character who is breathtakingly rude to other people yet seems oblivious to the offence they're causing. In the opening scene of The Social Network, Mark plays that role: he does nothing but insult Erika (they're only there because she "slept with the doorman"; she doesn't need to study because she's at a less important university) or ignore her ("I wasn't talking about China anymore, I was talking about me") and then seems flabbergasted when she tells him their relationship is over. The humour comes from watching him dig his own grave, especially when he ignores all the warning signs (Erica's horrified reactions) and just keeps digging.

I'm not suggesting that Mark Zuckerberg is written as a comedy character: he isn't. But Sorkin is a hugely witty writer and there are plenty of funny scenes in the film without it being a comedy. (The chicken cruelty episode always makes me laugh out loud!)

The opening scene in any movie is meant to be the before, and the closing scene is the after. So you see the progression the character takes, the arc if you will.

The opening scene of "The Social Network" is meant to introduce you to your protagonist. It's meant to show you a) he's smart, b) he's kind of a jerk, and c) he's motivated to do something big.

Do yourself a favor and actually read it - it's 10 pages long which is unheard of in screenwriting. Any writer who turned a script in like that, not named Aaron Sorkin, would've gotten laughed out of the room. Even though it's amazing writing, it's just not done like that. 10 Pages of two people talking is a play, not a movie.

So is it meant to be funny? Sure. Is it meant to make you kinda dislike your hero, sure. Is it meant to make you feel sorry for him because he has no idea how to properly talk to a pretty girl? Absolutely.

So how does the movie end?

Mark is now a billionaire, master of his own universe, yet still wonders about that girl. This doesn't show a complete character change as most films typically do. Again, it's Sorkin. He can do whatever he wants. He's the exception to the rule.