Judd Apatow’s new book, “Sick in the Head,” is a fascinating and revelatory cultural document. A collection of interviews with comedians conducted by Apatow between 1983 (when he was a teenager trying to figure out how to become a stand-up comedian) and 2015 (when he is arguably the most important producer of comedic material in Hollywood), “Sick in the Head” constitutes an important historical work documenting the rise of the class of comedians who came to prominence in the 1980s and 1990s — as well as the generation they would go on to influence.

Sick in the Head (Random House)

The earlier interviews are largely concerned with process: how a joke comes about, how a routine evolves. A frequent preoccupation in later interviews is social media, Twitter in particular. Given Apatow’s prominence on the medium (he has more than 1.2 million followers), that’s not terribly surprising. Nor is it shocking that many of his fellow comedians have embraced the opportunities provided by social media: These networks have given comedians new reach and exposed them to a wider range of opinions than ever before.

However, these new avenues have fundamentally changed the relationship between comics and their audiences. While the advantages for stand-ups who largely rely on self-promotion are obvious, the risks are equally great: Audiences’ newfound familiarity with the men on the stage and the intolerance the easily offended have for boundary-pushing work risk forever altering the workshopping process that Apatow and his subjects spend so much time discussing.

Apatow kibitzed with Albert Brooks in 2012 about the dangers of the medium (“Twitter is the devil’s playground. … We will lose the war to China because of Twitter,” Brooks says) and the angst it engenders (“I hope you die!” Brooks reads when he tweets about politics). In a chapter adapted from a 2010 commentary track recorded for an anniversary release of “The Cable Guy,” Jim Carey and Ben Stiller register similar complaints. “On Twitter, man, every once in a while every fiftieth person is like, ‘Who do you think you are? You better not be dramatic anymore. Don’t you be dramatic,” Carey says. “I’ll tweet something about Haiti and there’ll be someone who’ll tweet back, ‘Be funny! Who cares about Haiti!’ ” Stiller replies.

Apatow’s 2014 chat with “Saturday Night Live’s” Michael Che drives home just how much things have changed. “Now it’s this whole thing of you are what you tweet. I could know you for twenty-five years, I could have followed your whole career, but if you tweet something I don’t like, that means you’re just this kind of a person and you should never have a job again,” Che complains.

Che knows whereof he speaks. When he made a rather mild joke about Bruce Jenner not having to experience periods due to his transitioning to a woman at a later age, the arbiters of appropriateness excoriated Che. “Dear intellectuals, you are killing fun,” he complained; he and Colin Jost would later perform a sort of metajoke on “Weekend Update” about it, riffing on Che’s fear of cracking wise.

Twitter’s outrage mobs have always reminded me a bit of puritanical scolds: They sniff out heresies and denounce the heterodox, rejecting the defense that artists must have license to transgress the sensibilities of those claiming offense. Kurt Metzger, a (liberal, male) comedian who writes for (the liberal, feminist) “Inside Amy Schumer,” made a similar point in a recent interview on Marc Maron’s podcast, “WTF.”

Metzger, who left his family’s sect of Christianity many years ago, was discussing the way that his faith’s followers were admonished against being “a stumbling block to your brother” — that is, being someone who introduced doubt as opposed to being someone who reinforced faith. He thinks today’s comedy scolds are operating in a similar manner. “I think I’m a liberal, dude. These same kinda lefty kinda people have the exact same f—king, like, ‘Don’t stumble anyone out of being progressive, potentially. That’s, politics are most, the most important thing. I make a decision to laugh. I don’t just laugh. Maybe in heaven I’ll laugh one day. I filter it through my gender studies class and I, muh,’” Metzger says, letting the impression trail off while Maron chuckles.

Comedians are beginning to understand that the cliquish nature of social media — driven in part by the urge to rack up likes and faves and retweets by upping the demonstration of outrage — makes these platforms feel more like religious cults than comedy clubs. And cults have different mores than clubs. I remember being bemused when the social justice left flipped out on Daniel Tosh for joking that it would be funny to see a heckler raped. The controlling factor of that anecdote, at least to me, was not the invective from Tosh but the fact that it was aimed at someone who had violated the norms of the comedy club. As Louis C.K. explained via his pseudo-alter-ego Louie, a stand-up act isn’t a two-way street — you, the viewer, aren’t “allowed to participate.” But the comic is allowed to shut you up in the most vicious (vocal!) manner possible.

Twitter and Facebook, on the other hand, explicitly encourage participation. I tend to agree with Apatow et al that people on the medium behave bizarrely rudely toward celebrities. But it’s not surprising, exactly. The mores that govern social media are not the same as the mores that govern the Comedy Cellar. And the amplifying effect of Twitter can have a deleterious effect on the craft of comedy as envisioned by these performers.

“I think anyone should do whatever they like,” Jerry Seinfeld told Apatow in 1983. “I don’t think there should be any rules.”

“As long as it gets laughs?” the then-15-year-old Apatow asks.

“If it doesn’t get laughs, you’re not gonna get work, and you’re not gonna be a comedian,” Seinfeld replies. “So the audience ultimately decides. It’s a very democratic system.”

Seinfeld’s point is an interesting one in this context. The scolds will often claim that their censoriousness is simply an artifact of the marketplace at work. But this is misdirection. The aggrieved don’t leverage their power by unfollowing an offensive person or refusing to watch their routine. When Metzger defended a fellow comic whose routine was reviled by the social justice set, his newfound foes did not say they’d skip his stand-up act and force clubs to choose between a guy who could fill a room and a guy who can’t. Rather, they combed through his Facebook history before calling for him to be fired from “Inside Amy Schumer.”

As Metzger tells Maron, Schumer and Comedy Central ignored such pleas. Similarly, Comedy Central and Jon Stewart dismissed the denunciations of Trevor Noah when it was revealed he made a few questionable jokes about Jews and girls with tattoos. And here’s where we can see how to balance the rights of comedians to crack jokes with the rights of the perpetually outraged to vent their anger. You are allowed to participate with a comedian and his employer on Twitter in ways that you aren’t allowed to at the Improv. But the employers of these comedians are, similarly, allowed to ignore you.

Speaking as a fan of comedy? I hope they do.