Communication and community: Marisa Casillas investigates how culture affects childhood linguistic development

November 15, 2021

Learning to talk is one of the most visible and celebrated milestones in early childhood development. Many factors can affect this process, including community and culture. Marisa Casillas, Assistant Professor of Comparative Human Development at the University of Chicago, wants to understand how parental ideologies about how to talk to children shape the ways in which children learn language concepts and use language with others. Her most recent research examining differences across two distinctively different communities brings these factors to the forefront.

“There are huge differences in these ideologies across cultures, and they drastically contribute to how children spontaneously learn language through the course of daily interactions,” Casillas said.

Much of Casillas’ work is focused in two geographic areas: a Tseltal Mayan community in Chiapas, Mexico, and the rural Rossel Island community in Milne Bay Province, Papua New Guinea. Continuing the work she began in collaboration with Penelope Brown and Stephen C. Levinson, emeritus researchers from the Max Planck Institute for Psycholinguistics in Nijmegen, the Netherlands, Casillas is currently examining the different ways in which infants and young children encounter language in the typically multi-generational households in these communities. On the surface, communication differences are immediately evident: caregivers on Rossel Island interact with babies similar to the way people do in the United States. In the Mayan community, however, the ideas driving infant-caregiver engagement are very different: healthy infants are calm, and well-socialized children are keen observers of what is going on around them who do not expect to be the center of social or conversational attention. These different patterns of engagement are well-documented in past ethnographic work by Brown in both communities.

“The engagement is very loving but more focused on non-verbal communication. So, in combination with a cultural valuing of children becoming adept language observers, our hypothesis was that the Tseltal adults tend to speak directly to babies much less often than they do on Rossel Island,” Casillas explained.

Building upon her interest in exploring the cognitive processes that underlie language development, Casillas conducted a study using audio recordings to analyze children’s language landscapes across these two communities. The process involved securing a small recording device to children for a one-day period to obtain all the sounds they made and heard. Most recordings were from children under four years of age, although the range was from two weeks to six years old. Casillas obtained 55 recordings from the Mayan community and 57 from Rossel Island. The recordings were quite lengthy and not transcribed, so Casillas and her team randomly selected 10 children from each sample group aged three years or under and fully transcribed nine clips that were randomly selected from throughout the day, as well as 11 other clips from peaks in conversational and child vocal activity. This created a baseline of what sounds the children heard and produced, as well as what they heard and produced during their language “peaks” for the day.

Prior to analyzing the results, Casillas predicted the children from the Mayan community would hear less language than the Rossel Island children based on the known cultural differences between the two groups. Surprisingly, the results were comparable across each community, suggesting that differences in caregiver ideologies about talking to young children are likely most observable at the microscale of what caregivers say and do in individual interactions, and not at the scale of children’s overall language exposure, as measured here. One key difference the recordings showed was that children on Rossel Island were exposed to more direct language input from other children than those children from the Mayan community as they got older, which is consistent with prior ethnographic descriptions of large child playgroups and child independence from a young age in that community.

Casillas is currently building upon this work by looking at how children in these communities (and in Chicago) learn language from spontaneous speech, specifically through the process of real-time predictions about what will be talked about in conversation and understanding how predictions are improved as children grow and gain expert knowledge in their language and patterns of conversation used in their community. It may be that children in different communities rely on different skill sets to extract and employ language information from conversation in their home environments.   

“Children in some places may be better at learning from speech not directed at them than others,” Casillas said. 

She plans to develop a new line of research in the same communities focused on this question. Learn more about Casillas’ research on her website.