A COUPLE of weeks ago, I saw a stranger crying in public. I was in Brooklyn’s Fort Greene neighborhood, waiting to meet a friend for breakfast. I arrived at the restaurant a few minutes early and was sitting on the bench outside, scrolling through my contact list. A girl, maybe 15 years old, was sitting on the bench opposite me, crying into her phone. I heard her say, “I know, I know, I know” over and over.

What did she know? Had she done something wrong? Was she being comforted? And then she said, “Mama, I know,” and the tears came harder.

What was her mother telling her? Never to stay out all night again? That everybody fails? Is it possible that no one was on the other end of the call, and that the girl was merely rehearsing a difficult conversation?

“Mama, I know,” she said, and hung up, placing her phone on her lap.

I was faced with a choice: I could interject myself into her life, or I could respect the boundaries between us. Intervening might make her feel worse, or be inappropriate. But then, it might ease her pain, or be helpful in some straightforward logistical way. An affluent neighborhood at the beginning of the day is not the same as a dangerous one as night is falling. And I was me, and not someone else. There was a lot of human computing to be done.

It is harder to intervene than not to, but it is vastly harder to choose to do either than to retreat into the scrolling names of one’s contact list, or whatever one’s favorite iDistraction happens to be. Technology celebrates connectedness, but encourages retreat. The phone didn’t make me avoid the human connection, but it did make ignoring her easier in that moment, and more likely, by comfortably encouraging me to forget my choice to do so. My daily use of technological communication has been shaping me into someone more likely to forget others. The flow of water carves rock, a little bit at a time. And our personhood is carved, too, by the flow of our habits.

Psychologists who study empathy and compassion are finding that unlike our almost instantaneous responses to physical pain, it takes time for the brain to comprehend the psychological and moral dimensions of a situation. The more distracted we become, and the more emphasis we place on speed at the expense of depth, the less likely and able we are to care.

Everyone wants his parent’s, or friend’s, or partner’s undivided attention â€" even if many of us, especially children, are getting used to far less. Simone Weil wrote, “Attention is the rarest and purest form of generosity.” By this definition, our relationships to the world, and to one another, and to ourselves, are becoming increasingly miserly.

Most of our communication technologies began as diminished substitutes for an impossible activity. We couldn’t always see one another face to face, so the telephone made it possible to keep in touch at a distance. One is not always home, so the answering machine made a kind of interaction possible without the person being near his phone. Online communication originated as a substitute for telephonic communication, which was considered, for whatever reasons, too burdensome or inconvenient. And then texting, which facilitated yet faster, and more mobile, messaging. These inventions were not created to be improvements upon face-to-face communication, but a declension of acceptable, if diminished, substitutes for it.

But then a funny thing happened: we began to prefer the diminished substitutes. It’s easier to make a phone call than to schlep to see someone in person. Leaving a message on someone’s machine is easier than having a phone conversation â€" you can say what you need to say without a response; hard news is easier to leave; it’s easier to check in without becoming entangled. So we began calling when we knew no one would pick up.

Shooting off an e-mail is easier, still, because one can hide behind the absence of vocal inflection, and of course there’s no chance of accidentally catching someone. And texting is even easier, as the expectation for articulateness is further reduced, and another shell is offered to hide in. Each step “forward” has made it easier, just a little, to avoid the emotional work of being present, to convey information rather than humanity.

Jonathan Safran Foer is a novelist who delivered the 2013 commencement address at Middlebury College, from which this essay is adapted.