When my autistic son, Nat, was about 8, we learned that he loved looking at family photos on my husband’s computer. This discovery rocked my family’s world. Before then, we did not know that Nat enjoyed our faces. He had never seemed that comfortable looking at or talking to us. Perhaps he liked the unchangeable nature of pictures, their static predictability. Or maybe the stillness of photos gave him the space to process his thoughts.

“Go there,” Nat would say, pointing at an image from my mother’s house during Passover. Once we understood that the house, our family and the holidays were things Nat liked, my son Max started taking pictures of them and we’d put them on the laptop for Nat. Laptop photos gave Max something in common with his older brother, perhaps for the first time.

Sometime in the past year, Nat had a sort of mental growth spurt. This is not atypical with autism. In Nat’s case, he suddenly seemed to labor less over answering questions and he became very interested in other people. He was more alert, if more on edge; it was as if he had acquired a new sharpness.

Nat still has great difficulty finding words to communicate, but it seemed like he wanted to try. I realized that if I remembered to wait, to be quiet for a long time, he could often formulate an answer — terse yet perfect, crystalline.

Many fellow autism moms began urging me to get Nat an iPad, saying he could communicate through it. I was reluctant because I thought that Nat just could not link the concept of computer activity with speaking. He had never played video games, and he showed little interest in using the computer to learn. He did type the occasional e-mail, with heavy support from his teachers, but he did not seem to enjoy it.

One recent afternoon we weren’t doing much; I was online, checking e-mail and Facebook. For no particular reason, I called Nat over to look at my Facebook page. He must have been bored, for he came right away. He seemed fascinated with the little thumbnail images of all the people I know — many of whom he knows as well. An idea began to bloom.

“Hey, Nat,” I said, “you want to type on my Facebook page here?” To my surprise, he answered yes. I had no idea what to expect and sat back while Nat’s finger hovered over the keyboard, his thoughts slowly coalescing into words. He’d finally shout one out and I’d say, “Okay, type that!” Then he’d sound it out, using the invented spelling of kindergartners — but this was anything but babyish.

Seeing Nat’s words on the screen felt miraculous. One of the first things he typed was — not surprisingly — “look at pikerts” (look at pictures). I posted a note on my Facebook wall that Nat was typing. Moments later, responses began pouring in. It seemed like all my Facebook friends wanted to talk to Nat. I asked Nat if he wanted to say something back. He typed some responses, “hi” and “how you.” I wanted to shout, jump and kiss him all at once but I stopped myself. I had waited many years for communication like this, but my son is also a 22-year-old man. I encouraged him, but quietly, the way he needs it to be.

Nat and I soon created his own Facebook account — with him doing most of the typing. In sending out friend requests, I invited his two brothers, a tricky venture because they did not want to friend me or their father. But Max accepted Nat right away, without a word. And he has been “liking” posts on Nat’s page.

Nat’s is just one Facebook page out of nearly a billion. But in our family, glaciers are melting and mountains moving. My younger son asked me the other day why I had put Nat on Facebook. I thought for a moment, then told him the truth: “I don’t know. It just seems like he’s ready to join the rest of the world.”

“Okay, I’ll friend him,” he said. Four little words, but sometimes that’s all you need.