"When you're tapping along -- tapping the song -- it's inevitable that the music that goes along with the song accompanies the active tapping in your head," he explained. "Even though you know that the person on the other end of this experience doesn't have access to the music that's in your head, it's very difficult psychologically to get beyond that perspective and appreciate just how truly impoverished the stimulus is for the other person."
It's similar with e-mail, the researchers found.
When speaking face to face, people can use intonation and physical expressions to convey subtle emotions like sarcasm.
But in text-based communications, we often just assume the recipient will simply "get it."
"The bigger problem of course, is that even if you are aware that communicating over e-mail say, is imperfect at best, if you miscommunicate, somebody doesn't get what you said or they misinterpret something, the conclusion that people are likely to draw is that these people they're communicating with are idiots," said Epley. "Not that the e-mail was unclear and ambiguous."
Even worse, the sender may not know he or she has annoyed or upset the recipient.
"It's not just that there are bruised egos along the way," he said. "It's that there are unknown offenses that we're likely to commit."
As further proof we're not as good at text-based communication as we think, the group's work points to the existence of emoticons -- the little smiley faces, frowns, blushes and more that people type in an attempt to convey emotion in e-mails and IMs.
As the paper points out, there are hundreds of emoticons, but even their meaning is often unclear at best.
"If you were to say that you were disappointed with my work, and you put a frowning face, I have no idea how disappointed you are," Epley said. "Is this devastating or is this trivial?"
"Or if you put a single exclamation point versus three, is this scaled properly? Are you enthused three times more when you put three exclamation points instead of one? They're better than nothing, but they're far from perfect."
In some of the studies, the researchers allowed some subjects to use emoticons, while preventing others from using them. They found the emoticon users weren't more effective at getting their points across.
"We don't know quite why that is, but we have a couple of intuitions," explained Kruger.
"Given that people overestimate the obviousness of their sarcasm and humor and so forth, then there's no need to use an emoticon if it's already obvious."
If egocentrism is the core of the problem, does that mean we're all just a bunch of egomaniacs when we sit down at the keyboard? Kruger and Epley say not.
"It's really an innocent case of egocentrism. It is true that there are other examples of people's inflated sense of self, but this really isn't one of those," said Kruger. "This is the more innocent one that stems from the inevitable difficulty that is associated with perspective taking. It's difficult to get beyond your own perspective even when we know that we need to."
Instead, the researchers concluded that although e-mail and instant messages are incredibly useful, they still have clear drawbacks.
"We need to balance, I think, the limitations of e-mail -- which we've found in this work -- with the clear advantages that e-mail affords and I think those are many and significant," he said.
"It provides a cautionary tale in some sense, to the extent that we don't unwittingly offend, we might want to take that extra step -- both in constructing e-mail and also in interpreting it."