Early language access, not hearing status, predicts children’s grasp of number

Children exposed to ASL or spoken English from birth performed as well as hearing peers on key early maths skills, highlighting the importance of accessible language in infancy.

A new study suggests that the timing of language exposure, not hearing status alone, plays a decisive role in how children learn early number concepts. Researchers led by Marie Coppola at the University of Connecticut found that deaf and hard-of-hearing children who had access to either American Sign Language or spoken English from birth performed as well on key numeracy tasks as hearing children raised with spoken language at home. The work, published in Child Development, focuses on a milestone known as the cardinal principle: the understanding that the final number word in a count represents the total size of the set.

That principle is a foundation of later maths learning, and children typically master it between about three and a half and five and a half years old. Coppola told UConn that once children move beyond rote counting, they begin to grasp that the last word in the sequence is not merely a label but a way of naming the whole collection. The study argues that this step is especially important for deaf children, many of whom do not receive accessible language from birth because most are born to hearing parents who may initially be directed towards speech therapy and spoken-language support rather than sign language.

The research team assessed 178 children aged roughly three to seven, recruiting participants from specialist schools across the United States. Children were grouped by whether they had been exposed to ASL or spoken English from birth, or whether they started receiving either language later. According to the published study abstract and related database entries, the researchers tested how high the children could count, how accurately they could make sets of items, and whether they understood that counting words map on to actual quantities. The results showed that early exposure to accessible language, whether signed or spoken, was strongly linked to better performance on these tasks.

The findings add to earlier work showing that number-word knowledge is central to children’s understanding of quantity and that deaf children who gain early language access can develop age-typical mapping skills. Previous research has also suggested that early access to ASL can support vocabulary growth in deaf children born to hearing parents. Coppola’s team said the new study is the first to systematically compare the effects of hearing status, language modality and timing of exposure on children’s grasp of the cardinal principle and on their ability to build larger sets.

For parents, the message is direct: early, accessible language matters, and sign language can support mathematical development as effectively as spoken language. Coppola said the study was designed with families in mind, especially hearing parents of deaf children who may be uncertain about the best path forward. Her broader aim is to strengthen early-intervention guidance and to help shift attitudes among clinicians and service providers, who may still undervalue sign language despite long-standing evidence of its developmental benefits.