Our rapidly growing incivility started with the invention of the telephone-answering machine.

Before the answering machine’s widespread adoption, people answered their landline phones with a pleasant “hello,” eager to learn who was calling.

To be sure, says social scientist James Katz, answering machines were considered rude in the ’70s.

By the ’90s, however, most homes had them and lots of people were using them, quite rudely, to screen calls – people like my p...