Save for the Macarena, the most annoying dance a human can perform is that thing where you walk down the street and have to outsmart a pedestrian texting. At first it looks like they are going to run into you. Then they finally look up from their phones, at which point you have to figure out who is going to make a left or right turn. You both made a left turn and you realize it won’t work, so you both do a right turn, and it just goes on and on until you finally get angry enough to yell at them.
Call it the Six-Step Smartphone. Grab your partner, do-if-do, and throw him in the street.
We’ve all danced this maddening dance, but now scientists have shown how a pedestrian distracted by a phone can create a mess not just for you, but for a crowd in general. Researchers at the University of Tokyo and Nagaoka University of Technology set up “two-way flow experiments” in which two groups of 27 people (one team wearing yellow caps, the other wearing caps red) marched abreast. In each experiment, one of the groups included three people looking at smartphones. Researchers placed these distracted walkers in the front, middle, or back of the pack, while cameras above tracked each other’s routes and speeds.
In a control experiment in which no one was distracted, the researchers observed a phenomenon described earlier, known as lane formation: when the two groups came into contact, people lined up in two or three. columns. In other words, it’s not that one group sank perfectly one way and the other group sank the other, forming two great lanes. If you look at it from above, the intermingled crowds look more like stripes on a flag – a single column of red hats, then a single column of yellow hats, then another column of red hats, and so on. People in a crowd therefore tend to fall into a leader’s tracking formation, allowing pedestrians in front of the crowd to work their way through approaching humans.
Each crowd has a few leaders in front, and each of them scans the movements of their counterparts directed in the other direction to avoid collision. This interaction between leaders is known as mutual anticipation. “If it’s you and me, at the same time I’m trying to predict where you will be in the future, and you are trying to predict where I will be in the future,” says Claudio Feliciani, computer scientist at the University of Tokyo, co-author of a New paper describing the experiences in the journal Scientific progress. Basically you are making split-second assumptions about how that person behaves and how you should react appropriately. “And this is the mechanism that makes it possible to have this type of collective training of models,” adds Feliciani.
If you get lost in your phone, however, that interpersonal relationship, however fleeting, breaks down. The person approaching you watches your movements and anticipates your behavior, but you don’t reciprocate. You’re adrift, and that means so are the people who follow you. When you finally make contact with someone in the approaching crowd, you stumble upon the Six-Step Smartphone, and the effects of that hesitation trickle down to your followers like a multicar stack.
Feliciani and his colleagues have proven this by using their volunteers wearing hats. In the experiments, pedestrians distracted by the phone placed in front of a crowd slowed down everyone behind them. The distracted leaders could not negotiate this subtle but complex nonverbal interaction with their counterpart at the head of the approaching group. So if you look at the trajectories of the way a red hat individual reading a phone walked, instead of the flag striped aisles of a normal crowd, there is just a confusing mess of red hat people everywhere. (See the mess game below.) Indeed, the researchers found that the distraction of the distracted pedestrian would disrupt the behavior of his counterpart in the yellow hat, who was in fact observant, compromising the effectiveness of the pedestrian. other group.
But the researchers didn’t see the same effect when distracted pedestrians were placed in the middle or back of the crowd. This is because, even when distracted, pedestrians could play following the leader with the person in front of them – they had a body they could follow, even with their faces buried in their phones. “When they’re distracted, the people behind also get lost,” says Feliciani. “The people behind, if they’re distracted, it’s not that important, because they can somehow follow the others.
