Researchers at Western Washington University wanted to test how alert cell phone users were of their surroundings compared to the general population. So they dressed a student as a clown and had him ride his unicycle around campus:
Link via Gizmodo | Image: Ira Hyman
The observers asked walkers if they had noticed anything unusual, and for those who didn't, they asked specifically if they had seen the unicycling clown. Even when directly asked, the cell-phone users were less than half as likely to notice the clown as those listening to music players or single individuals without any electronics. People who walked in pairs were the most likely to see the clown.
"So it's not the conversation that's the problem; it's not an electronic device that's the problem," Hyman told LiveScience. "It's something about a cell phone conversation is where the problem is."
He speculates, as do other researchers, that when talking to someone in person you both can modify your conversation based on the environment, so if a clown, say, pops up you can both look up. "That's not the case with the cell-phone conversations," Hyman said.
Link via Gizmodo | Image: Ira Hyman
Talking on the phone, I think, puts our minds in a similar state where we lose focus on our surroundings. Like the book thing above, i don't think an electronic device is necessary at all, or even oa conversation. So I think they are on the wrong track there... It's more like.. its an object that can occupy a person's mind/attention strongly. I don't think a music player is sufficient for that for most people. But a conversation with a disembodied voice... engages their mind to fill in the context that lacks when they are not present (expressions, body language, imagining things talked about, etc.)
Also totally agree with narwhal.