Impulse control is unfashionable as well as unpresidential, but perhaps you should resist the urge to trip people who stride briskly down the sidewalk fixated on their phone screens, absorbed in texting and feeling entitled to expect others to make way. New technologies are shaping behaviors and dissolving civilities.

In 2005, Lynne Truss, in her book “Talk to the Hand: The Utter Bloody Rudeness of the World Today, or Six Good Reasons to Stay Home and Bolt the Door,” presciently said we were slouching into “an age of social autism” with a “Universal Eff-off Reflex.” Long before progress, under...