By Faye Wolfe

A woman and her baby son take their seats. It’s time for Applesauce Theater. The lights go down, the screen goes up, and the play begins, a minimalist tale of a stand, a spoon, and a dollop of pureed fruit. The action on the tiny “stage”—a table behind a screen that flies open and closes with a snap—is absorbing to its audience, but the real star of the show is the 14-month-old spectator on his mother’s lap, whose reactions and actions to what he sees are being recorded on video for future analysis. Which hand will reach for the spoon? Will the applesauce end up in his mouth? When will he decide the show is over?

In the next room, part of the other audience observing the drama on a monitor is Rachel Keen. The UMass Amherst psychology professor is a highly regarded researcher who, over the years, has investigated a remarkably wide range of topics within her field of child development, including psychophysiology, memory, and the topic du jour: reaching. One of the grad students she advises, Amy Joh, is “running babies” in this series of sessions to learn more about the mental processes behind a baby’s reaching. Keen’s career attests to a deep intellectual engagement with her work, but asked after the session what it is about studying children that inspires her, she bursts out: “You saw how cute that kid was!”

During her nearly 40 years on campus, Keen has probed cognitive development in the fastest-growing minds among us. “I’ve always been interested in children,” says Keen. I started as an elementary ed major [in Berea College in Kentucky], then I got interested in the scientific element of child development. . . . Children are pretty adorable, innocent—and so smart, little scientists. When you look at a baby, what do you see?” She answers her own question: “Those big eyes,” her own widening.

Like those little scientists, Keen brings curiosity, a prodigious appetite for learning, and a wide-eyed delight to exploring the questions of what children do know, and when they know it. She’s a big scientist, in accomplishment and reputation. Among other topics, she has researched “frequency envelopes,” “multimodal perception in human infants,” and “newborn heart-rate response,” with grants from such major funding sources as the National Science Foundation, the National Institute of Mental Health, and the March of Dimes. In 2006, she was elected a fellow of the American Academy of Arts and Sciences, along with two former U.S. presidents and a Nobel Prize winner.

Keen has also done significant work in the field of acoustics. The Clifton Effect, an auditory adjustment humans make to echoes, is named for her (she dropped Clifton as her last name in 2003). Being named a fellow of the Acoustic Society of America was “one of the highest honors,” she says, of her career. “It’s especially satisfying that I’ve had success in two very different fields. Many of the people who know me for my work in child development don’t even know of my work with adults in acoustics, and people in acoustics don’t know I work with children.”

“I am very much a creature of the lab,” Keen wrote a few years ago, “an empiricist rather than a theorist. . . . Nothing is more enjoyable to me than designing an experiment, then watching infants in the lab bear out a prediction. I am also delighted when they do something that surprises me.”

Keen’s interest in reaching, which has led to Joh’s spoon sessions like the one described earlier, came out of one such surprise. Keen was investigating how babies see and hear in the dark using a “sounding object,” such as a rattle, in and out of reach, when, she recalls, “I’m thinking, ‘Gosh, reaching is interesting.’”

Most parents probably don’t take to their camcorders to capture the moment of, or even remember Baby’s first reach, which happens around three or four months of age. Still, it’s a watershed moment, when a child moves beyond passive observation to active participation in the world. And when your daughter grabs hold of your earring and pulls, not only is she showing off her mastery of certain physical skills, she’s also applying her sense of shape, size, distance, the object as “other.” By age six months, most babies have the basics down; six months later, says Keen, “they’re experts.”

They still get boggled, though, by a spoon in a “difficult orientation.” Babies by then have started to favor one hand or the other, and in the applesauce experiments, they will use that preferred hand to pick up the spoon whether the handle is closer or farther away. “They’ll use the ulnar grip sometimes,” Keen explains, demonstrating the awkward grasp of a spoon with its bowl-end away from the mouth. “They always get the food. They always get the food, and there are many ways to do that, but only one efficient way, using the radial grip.”

As their minds grow, babies become able to rotate the object mentally before they ever make a move. “By 19 months, it’s like clockwork,” says Keen. “They pick up the spoon with whichever hand is more convenient.”

Keen is an old hand at designing experiments that test children, as well as ones that test adults, so she understands the particular challenges of plumbing the depths of young minds. The literature reveals them matter-of-factly: trials that succumbed to “fussiness” or ended because “the subjects climbed onto the table.”

“You have to be realistic when you’re testing kids,” says Keen. “You take advantage of their innate interests.” Three-month-olds like looking at things; activity-oriented tests work better with older babies. Keen’s experiments make room for parents, so they can be present but not skew results. “It takes time to get the child and the parent comfortable with the room, the people. If you rush it, it doesn’t work,” says Keen, adding cheerfully, “it might not anyway. Babies know how to take themselves out of a situation they don’t like, by crying, getting down, falling asleep. An experiment’s success depends to a tremendous degree on the facility of the experimenter.”

You learn from the “amazing failures,” she notes, as well as successful trials. A 14-month-old repeatedly using the ulnar grip says a lot about where humans are at that stage of life. When babies figure it out, it’s always thrilling. “You can practically see the wheels turning in their heads,” Keen says.

It also gets to something profoundly distinctive about humans. “Our entire existence, we are planning for the future. When we get up in the morning, we’re anticipating crossing the room and what we’re going to be doing that day,” says Keen. “We’re thinking about our IRA, our health proxy, our Christmas shopping. All these things we do toward planning for the future. Do dogs or cats anticipate, think about the future? No. Monkeys? It’s less clear,” says Keen.

Despite her many years of studying children and being the mother of two daughters and doting grandmother of a four-year-old, Keen is not prescriptive about parenting. “Lots of things work; there’s not one way. The relationship between the child and the parent is important. If you have a good relationship, there are many many ways you can do it. Thank goodness!”