Toward the end of lunch, Phoenix Ferragame, 17 months old, raised both hands in front of his chest and tapped his fingertips together.

His mother smiled.

“You want more? More chips?” Gina Ferragame asked, mimicking the hand movement and then passing the bowl to her son.

For parents, hardly anything is as satisfying as being able to communicate with their children. But speech requires development of three muscle groups. Toddlers typically have motor control of their hands and fingers months sooner.

Teaching a short vocabulary of American Sign Language – milk, more, please, and a handful of other words – is so simple that parents are networking, classes are spreading, and how-to sites are booming.

Ferragame and her husband began working on basic signs with their older son, Theo, when he was 5 months old.

“I saw a response immediately,” she said. “I was inspired by the fact that I could acknowledge him.”

Theo, now 3 years old, verbalizes well. The other day, however, he touched his chin with his fingertips and extended the hand out and down, palm up – thank you.

“It’s nice, as a mom, to hear – or see, really – please and thank you through the day,” said Ferragame, 35.

Using signs both before and after the boys started to talk resulted in fewer tears and tantrums in their Mount Airy, Pa., home, she said.

Children often can communicate faster with gestures or sign language than with speech, reducing their frustration at not getting what they want. And experts say that signing early can help with language development of all kinds later.

There is no consensus that early signing can bring improvement in IQ scores, as some advocates suggest. But almost everyone says that the positive parent-child interaction involved in teaching and using sign language is beneficial.

“What you are really doing is interacting with your child,” said Kathy Hirsh-Pasek, a professor of psychology at Temple University who specializes in language development. “The more you interact with your children, the better their language skills are going to be, so whatever gets parents to do that, it is a positive thing.”

The process is straightforward and time-consuming – lots of repetition of both words and signs like milk and eat and more when your child is thirsty, hungry, or wants more of anything. Often it takes months of consistent effort before the child begins to sign.

Hirsh-Pasek and other experts say there is no evidence that learning sign language will limit speech development, especially since the process involves both verbal and nonverbal communication.

If children were taught sign language as a true second language, it would be the equivalent of growing up in a bilingual household, said Gary Emmett, director of hospital pediatrics at Thomas Jefferson University, who often lectures on child development.

“We know that if you grow up in a truly bilingual home … children will start to speak about one month later, but they will speak both languages fine,” he said. “It is a language-rich environment that really helps children develop.”

For example, Emmett said, students who do the best in school have heard about 10 times the number of words at home as the poorest students.

Linda P. Acredolo, an emeritus professor of psychology at the University of California-Davis, is a leading proponent of teaching hearing children to sign, and her federally funded research found clear benefits.

“These kids had a jump start in language and were able to ask questions earlier and engaged with adults earlier,” Acredolo said. “Of course it would benefit their intellectual development.”

By JOSH GOLDSTEIN