Rain Bosworth studies how deaf children experience the world

The deaf experimental psychologist has found that babies are primed to learn sign language

Rain Bosworth smiling and looking at a parent-child pair to her left. She has blonde hair and blue eyes and wearing blue button-up shirt. The parent is looking at an iPad, sitting in front of them on a round table. The iPad is displaying what appears to be a video with a person signing. The parent has black hair and wearing a navy polka dot shirt. The child is sitting on the parent's lap and staring at Bosworth.

Work by deaf experimental psychologist Rain Bosworth (left) suggests that babies have an innate sensitivity to sign language.

Mike Guinto

In a darkened room in Rochester, N.Y., a baby girl in a pink onesie peers at a computer screen. Wherever she looks, an eye tracker follows — recording her gaze patterns for future analysis.

The baby, about 6 months old, is neither deaf nor hard of hearing. And she’s never been exposed to sign language of any sort. But somehow, she and others her age can tell the difference between gestures and formal signs. When a woman onscreen uses American Sign Language, these young babies tend to pay attention, locking their eyes on her hands. When she makes non-sign gestures, babies often look at her face instead or look away.

“I thought it was pretty remarkable,” says Rain Bosworth, an experimental psychologist at the Rochester Institute of Technology whose team reported the results in 2022 in Frontiers in Psychology. The work suggests that babies have an innate sensitivity to sign language.

That idea — that infants are primed to pick up any language, whether spoken or signed — can be hard for people to believe, she says. After all, we live in a hearing-centric world. “There is a bias to think of spoken language as somehow superior to signed language.” But that’s just not true, she says. “Sign language is a full and real language, just as powerful as English.”

By tracking infants’ gaze patterns (red dots) as they look at a computer screen, Rain Bosworth’s team can figure out what captures their attention. Infants around 6 months old, for example, tend to lock their eyes on the hands of people using American Sign Language.

Bosworth investigates how people learn and process sign language through studies on deaf and hearing people’s use of vision and touch. With this and other research, she aims to understand how early sensory input — like seeing parents use sign language or hearing scientific jargon spoken at home — shapes our development.

In 2022, after three years at RIT’s National Technical Institute for the Deaf, Bosworth established a new research lab there dubbed PLAY Lab (for Perception, Language and Attention in Youth). She’s passionate about reframing negative perceptions of sign language and deaf people. Deaf herself, Bosworth feels she’s the right person to come up with study questions, she tells me via interpreters on Zoom. “I think about science nonstop 24/7.”

Bosworth’s career is a testament to her tenacity, says Karen Emmorey, a cognitive neuroscientist at San Diego State University. Deaf researchers can face challenges hearing people may never consider, like being asked to arrange interpreters for lectures, meetings, social events — and interviews. But Bosworth is stubborn, Emmorey says. “She’s going to persevere and do what she needs to do to succeed.”

The window for language learning

The vast majority of deaf kids in the United States — more than 90 percent — have parents who can hear. Even today, it is not uncommon for audiologists and physicians to advise these parents to avoid sign language, Bosworth says. Instead, kids are encouraged to use cochlear implants and read lips. There’s this incorrect thought that sign language will impair speech development, she says. Recent evidence suggests that learning sign language may actually boost a child’s spoken vocabulary.

Bosworth was born in San Francisco to hearing parents and grew up in Los Angeles. Sign language was prohibited at her school, so her first brush with it came on the school bus, when she was 6 or 7 years old. She and other deaf kids made up their own signs to communicate. That cracked the door to a rich new world of visual language, and a friend she met in high school kicked the door wide open. Bosworth’s friend was deaf and so were her parents and siblings. “I was like, ‘This is the best thing I’ve ever seen,’” she remembers thinking.

She sees reminders of that experience in students who come to the National Technical Institute for the Deaf for the first time. The institute serves more than 1,100 deaf and hard-of-hearing students, and in classrooms, laboratories and public spaces, students, faculty and staff use sign language. Many students who come to NTID were the only deaf people in their schools, Bosworth says, and have experienced isolation and barriers to learning. When they arrive, “they’re definitely on cloud nine,” Bosworth says. “This is like a second home to them.”

It’s a second home for Bosworth too, a place where she can unspool her curiosity and let it fly. There’s a strong inclusive mentality that she’s proud to contribute to. “I’m able to be a role model to all of these students of what a deaf person can do.”

Bosworth’s research is filling in a more complete picture of how deaf and hearing kids acquire language — and how that process changes as children grow and take in new information, says Jenny Singleton, a linguist at Stony Brook University in New York. For instance, Bosworth has shown that, around one year of age, all hearing non-signing babies tend to lose their innate ability to discriminate between signs and gestures. Her team has also found that these older babies no longer pay special attention to certain types of fingerspelled words.

Both results suggest that the window for learning sign language closes somewhat with age, similar to spoken languages.

Rain Bosworth interacting with a child sitting next to her. Bosworth's blonde hair is pulled back into a ponytail, and she's wearing a short-sleeve navy shirt that displays the RIT logo in orange. The child. who has short blonde hair and wearing a navy hoodie, is watching Bosworth cutting a piece of paper with a pair of scissors. They are both sitting at a round table, which has a sign that reads, "Make a brain hat."
At an event at the NTID PLAY Lab, Rain Bosworth teaches kids in the community about the brain.Matthew Sluka

Bosworth’s work builds on a foundation established early in her career; as a graduate student at the University of California, San Diego, she examined the visual abilities of deaf adults. She’s melding tools and methods of inquiry from two fields, linguistics and visual perception, “in a really impressive way,” Singleton says.

Beyond the window for language learning, Bosworth is also investigating how kids explore the world and how they play. How does a child’s background and hearing status influence their behaviors? Do deaf kids rely on their sense of touch more than hearing kids? Do specific types of play affect how children learn language?

A need for more deaf role models

For Bosworth, it’s not enough to make scientific strides in a field dominated by hearing people. She wants to bring deaf people along with her by mentoring students. “I want them to get on this research bus with me,” she says.

Over time, she hopes for more deaf role models in academia and more research that, like her own, casts deaf people in a positive light by highlighting their strengths rather than looking for deficits.

In grade school, Savannah Tellander, a graduate student in Bosworth’s lab who is hard of hearing, sometimes felt as if teachers assumed she wasn’t as smart as other kids. “They would usually doubt me before they ever met me,” she says. Those kinds of experiences are part of what drew her to Bosworth’s lab — along with an interest in helping people understand how to support deaf kids’ cognition and language. And she was impressed from the get-go with Bosworth’s zest for mentoring.

Tellander remembers meeting Bosworth upon first arriving at NTID, after moving from California with no friends or family nearby. Bosworth’s eyes lit up talking about her own experiences with her adviser. “She was really, really excited to be a mentor,” Tellander says.

Bosworth is one of those people who shows up, she says. On any given day, you may find her helping students write a research proposal, teaching them how to make a poster or finding time outside of work to attend a colleague’s art show. “She supports the hell out of people.”

It’s important to Bosworth that deaf students know that, despite what the world may be telling them, they have their own strengths and can lead successful lives. “I see deafness as a life experience that shapes who we are just like any other cultural experience,” Bosworth says. “I think that being deaf is wonderful.”

Meghan Rosen is a staff writer who reports on the life sciences for Science News. She earned a Ph.D. in biochemistry and molecular biology with an emphasis in biotechnology from the University of California, Davis, and later graduated from the science communication program at UC Santa Cruz.

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