It was a skill I perfected when I lived and walked in New York City: When faced with a pedestrian barreling right at me, I learned to quickly glance down. To keep eye contact meant we’d likely find ourselves in one of those awkward dances where one heads right thinking the other will head left, only he heads right too. Looking down breaks the cycle and avoids collisions.

This behavior would not surprise Alexandra Horowitz. In her book On Looking, which I mentioned a few weeks ago, she describes pedestrian behavior as quick, fluid and fish-like. It depends on three basic rules (alignment, avoidance and following the person in front of you) plus a series of quick calculations made because we pay attention to each other.

Most of the time, people look where they are going. So the gaze is the giveaway. You can even follow someone’s head, because people actually incline in the direction they want to go.

The one type of pedestrian that breaks this rule: the phone talker. “Their conversational habits change the dynamic of the flowing shoal,” Horowitz writes. “No longer is each fish aware, in a deep, old-brain way, of where everyone is around him.”

And this means that my looking-away skill doesn’t work as well anymore.  Which is something I already knew, in my deep, old-brain way.