Across languages and cultures, words that help direct caregivers’ attention are likely to be among the first children learn and use frequently, according to a new Cornell study that is the largest ever, by sample size, of early vocabulary development in an Indigenous language.

The early use of words like “this” and “that” has been documented in widely spoken languages such as English, Spanish and Mandarin, which have relatively simple systems for demonstratives, said Amalia Skilton, a linguistics scholar and Klarman Fellow in the College of Arts and Sciences (A&S).

Skilton observed similar patterns among 45 Ticuna speakers in Peru, suggesting that children’s strong drive to share attention has similar effects on language learning – especially on the first words – even in languages that differ structurally and that are spoken in very different social settings.

“Children learn demonstratives that call others’ attention to objects – such as ‘this/that’ and ‘here/there’ – at extremely young ages, when they know very few other words,” Skilton said. “‘This’ and ‘here’ show up just as early as stereotypical first words like ‘mama.’”

Demonstratives play a “starring role” in language development, Skilton writes in “Learning Speaker- and Addressee-Centered Demonstratives in Ticuna,” published April 7 in the Journal of Child Language. They are one of the main tools for directing what linguists call joint attention, which allows us to label objects with names, coordinate our actions and cooperate.

“Sharing attention is the infrastructure for the rest of language and social interaction,” Skilton said.

English has only two primary demonstratives (“this” and “that”) but some languages have up to a dozen. Ticuna, spoken by roughly 69,000 Indigenous people living along the Amazon/Solimões River in Peru, Colombia and Brazil, features six demonstratives, four of which were studied because of their more common usage.

Over more than a year in Cushillococha, Peru, a community of about 5,000 that relies on subsistence farming, Skilton recorded children ages 1 to 4 at play and interacting with caregivers in their homes. She analyzed Ticuna language development captured in nearly 15 hours of video samples.

Despite their small vocabularies, 12 of the 14 one-year-olds observed in the study said “this/that” or “here/there,” demonstrating the universal drive to share attention. Skilton said the research confirms that caregivers can expect children to start using those words at around 12 to 18 months old “no matter what language they speak.”

But the type of demonstratives used shows that while very young children are eager to share attention, they have difficulty understanding others’ perspectives. Ticuna children learned “egocentric” demonstratives – equivalent to “this/here near me” – about two years earlier than “interactive” demonstratives like “that/there near you,” Skilton found. And they used those egocentric words more often than adults, accounting for as much as 15% of all words spoken.

It’s already known that children have trouble understanding what others believe or know. Skilton said her research adds the finding that young children also struggle with understanding how other people view objects in space. She believes that’s a function of cognitive development, not the learning of any particular language.

Thus, Skilton said, parents and other caregivers shouldn’t necessarily be concerned if children under age 3 use interactive words incorrectly.

“While adults think of these words as simple,” Skilton said, “their meanings are fairly challenging for children to understand at young ages and having trouble with them is a typical part of child development.”

Skilton plans to return to Peru to continue her research that comprises the first comprehensive study of joint attention development in a non-Western setting, shifting her focus to children’s use of pointing gestures to direct adults’ attention. She is collaborating during her three-year Klarman fellowship with faculty host Sarah Murray, associate professor in the Department of Linguistics (A&S).

Skilton’s research has been supported by a National Science Foundation (NSF) Graduate Research Fellowship, an NSF Documenting Endangered Languages Doctoral Dissertation Research Improvement Grant, and an NSF Social, Behavioral and Economic Sciences Postdoctoral Research Fellowship.