If you think it’s juicy content that keeps people tuned in to others’ cell calls, however, think again. The most mundane cell phone conversation, as Liberman found out at the gym, can be the hardest to ignore. “It was maddening because I couldn’t figure what could be going on that was causing her to repeat the same thing over and over again,” Liberman says. “It wasn’t in itself very interesting; what was attention-getting was the unexpected fact of repetition. What was the conversational setting that would lead to this?”

This perfectly embodies Emberson’s theory of what makes a cell phone conversation—which she and her coauthors dub a “halfalogue”—annoying. The repetition of the girl on the treadmill was annoying because it was distracting. It was distracting because, try as we might—and we do try—we can’t even imagine how that conversation would make any sense.

The neighborhoods nearest to the campus of the University of British Columbia at Vancouver are expensive—too expensive for students, says Emberson, who was a student there and didn’t live near campus. She lived a forty-five-minute bus ride away, which translated to a lot of commuting, which translated to a lot of reading.

When Emberson was in college, cell phones were just starting to get popular. She didn’t have one, and they annoyed her, especially on the bus. She wanted to read her essays on the philosophy of mind, but she found herself distracted by her bus-mates’ conversations. “Being an academic, I couldn’t stop at just being irritated,” she recalls. “I started thinking, ‘Why was I irritated?’ I couldn’t tune it out, and I used to think it was because I was nosy. But I actually didn’t want to listen. I felt myself forced to, almost. For most people, that’s not enough to go and do a study about it.” It was for Emberson, though, who is now at Cornell University. She devised a study to test her hypothesis on why cell phone conversations are so irritating.