It's clear that texting impairs our ability to walk. If it didn't, we wouldn't have so many war stories of walking into trees/each other/street lights/stationary objects. Here's a particularly embarrassing anecdote, from an anonymous Atlantic video executive producer, who was texting while walking through Washington, D.C., during Polar Vortex, Part I:
"I walked into a low-hanging tree branch and spilled coffee all over my jacket. It was a water-proof jacket, and the little beads of coffee froze to the jacket. Someone was in front of me and saw everything and gave me a look like 'what are you doing?'"
In this anonymous person's defense, the Pew Research Center (which has actually studied this) found in 2012 that 53 percent of all adult cell phone users have bumped into someone or something – or been on the receiving end of such a bump – thanks to this kind of distracted walking:
Now, scientists are starting to identify exactly what we're doing wrong. Researchers from the University of Queensland in Australia have just published a paper in the journal PLOS ONE confirming that, in fact, texting changes how we walk, right down to our "gait kinematics."
They studied how 26 healthy people walked a short distance (8.5 meters) in three scenarios: while walking normally, while reading texts on a cell phone, and while writing a text themselves. Eight cameras were positioned along the walking path to measure the speed and gait of how people walked, as well as the positioning of their heads, torsos and arms.
The paper itself has some amazingly intricate data on the rotation motion of the pelvis and thorax under each scenario. But suffice it to say: We walk much slower when handling a cell phone (even moreso while texting than reading), and we're not very good at sticking to a straight line. Not surprisingly, we tend to keep our heads down, our necks immobile, and our arms locked at our sides. We don't swing our arms, which can be a crucial part of staying balanced while moving.
Overall, we behave in a way that tries to optimize typing rather than walking, that's more geared toward keeping that little screen stable in our field of vision than keeping ourselves stable.
To illustrate this, here you can watch our own Amanda Erickson walk down a hallway in the Atlantic Cities office. On the left, she's walking normally. On the right, she's trying to type the same phrase used in the study: "The quick brown fox jumps over the lazy dog."
We did not have our own three-dimensional movement analysis system, so you'll have to parse the subtle differences with your eyeballs. But, clearly, it takes Amanda much longer to navigate the hallway while texting, she wanders off-course a bit, her arms barely move at all, and she's not taking in much of what's going on around her. She kind of looks like you could easily tip her over.
Now, picture a hundred pedestrians doing this same thing in a crowded, obstacle-filled public park.
Extra thanks in the name of science to Amanda and Paul Rosenfeld.