Some years ago, I was awakened early one morning by a phone call from a friend. She had just broken up with a boyfriend she still loved and was desperate to justify her decision. “Can you believe it!” she shouted into the phone. “He hadn’t even heard of Pushkin!”

We’ve all been there. Or some of us have. Anyone who cares about books has at some point confronted the Pushkin problem: when a missed  or misguided  literary reference makes it chillingly clear that a romance is going nowhere fast. At least since Dante’s Paolo and Francesca fell in love over tales of Lancelot, literary taste has been a good shorthand for gauging compatibility. These days, thanks to social networking sites like Facebook and MySpace, listing your favorite books and authors is a crucial, if risky, part of self-branding. When it comes to online dating, even casual references can turn into deal breakers. Sussing out a date’s taste in books is “actually a pretty good way  as a sort of first pass  of getting a sense of someone,” said Anna Fels, a Manhattan psychiatrist and the author of “Necessary Dreams: Ambition in Women’s Changing Lives.” “It’s a bit of a Rorschach test.” To Fels (who happens to be married to the literary publisher and writer James Atlas), reading habits can be a rough indicator of other qualities. “It tells something about ... their level of intellectual curiosity, what their style is,” Fels said. “It speaks to class, educational level.”

Pity the would-be Romeo who earnestly confesses middlebrow tastes: sometimes, it’s the Howard Roark problem as much as the Pushkin one. “I did have to break up with one guy because he was very keen on Ayn Rand,” said Laura Miller, a book critic for Salon. “He was sweet and incredibly decent despite all the grandiosely heartless ‘philosophy’ he espoused, but it wasn’t even the ideology that did it. I just thought Rand was a hilariously bad writer, and past a certain point I couldn’t hide my amusement.” (Members of theatlasphere.com, a dating and fan site for devotees of “Atlas Shrugged” and “The Fountainhead,” might disagree.)

Judy Heiblum, a literary agent at Sterling Lord Literistic, shudders at the memory of some attempted date-talk about Robert Pirsig’s 1974 cult classic “Zen and the Art of Motorcycle Maintenance,” beloved of searching young men. “When a guy tells me it changed his life, I wish he’d saved us both the embarrassment,” Heiblum said, adding that “life-changing experiences” are a “tedious conversational topic at best.”