Deaf infants who have been exposed to American Sign Language are better at following an adult's gaze than their hearing peers, supporting the idea that social-cognitive development is sensitive to different kinds of life experiences.
Gaze-following behavior, or looking where another person is looking, is an important milestone in child development that plays a key role in communication and social-cognitive processes. Prior research has established that an infant's ability to gaze follow emerges on a clear developmental timetable, but the first experimental study of Deaf infants of Deaf parents suggests these important markers are more malleable than previously thought.
"By only studying the developmental patterns of hearing infants until now, we may have overlooked the human potential for a broader range of visual and cognitive capacities in early childhood," said the study's co-author, Jenny Singleton, a linguistics professor at The University of Texas at Austin.
In a paper recently published in Developmental Science, Singleton, along with Rechele Brooks and Andrew Meltzoff of the University of Washington's Institute for Learning & Brain Sciences, examined the gaze behavior of deaf infants of deaf parents, comparing it with hearing infants of hearing parents, to test how infants adapt to communication modes to which they are exposed.
(WATCH NOW: Singleton and Brooks explain their most recent study.)
The study showed that Deaf infants exposed to American Sign Language (ASL) by their Deaf parents demonstrated advanced eye-gaze behavior compared with hearing infants not exposed to a sign language. Not only did Deaf infants excel at following an adult's gaze to a specific object, they also demonstrated more advanced "checking-back behavior," or looking back to the adult for more information.
The researchers hypothesize that being reared by parents fluent in ASL gives Deaf infants extra experience in picking up and seeking visual cues, providing them with a "visual learning ecology" that supports advances in development. But the researchers stress the need for future studies to determine what other mechanisms may influence how infants "learn to look," which ultimately promotes language development and social-cognitive behaviors.
"This interdisciplinary work combines research techniques from linguistics, developmental science and experimental psychology," Brooks said. "Together we learned that infants are exquisitely adapted to the culture and ecology in which they are reared. Both the hearing and the Deaf children develop efficient ways to understand and communicate with others in their environment."
The researchers suggested future experiments should evaluate behaviors of Deaf children who are not exposed to ASL to test whether advanced gaze behavior is a result of how Deaf parents interact with their infants, or whether it's a natural compensation for individuals who primarily engage the world through their vision.
"Finding that this infant behavior can be shaped by experience is a significant observation - one that pushes us to consider both infants' natural motivation to communicate with other people and their flexibility of learning to communicate through a variety of modalities," Singleton said. "With UT Austin's expertise in sign language acquisition and UW's expertise in infant gaze following, we are truly well positioned to tackle this very important question together."