Delayed First Language Exposure Negatively Impacts Representation of Small Quantities: Evidence from Deaf and Hard-of-Hearing Children.

Most deaf and hard-of-hearing children are born to hearing parents, often delaying exposure to their first language. This negatively influences development of not only language, but also many other aspects of cognition, including exact representations of large quantities. The core knowledge view of numeracy predicts that delays in language exposure should not affect nonverbal representations of small quantities (1-3). This study is the first to investigate effects of language modality (spoken vs. signed) and timing of language experience (early, from birth vs. later) on the representation of small quantities of objects. We adapted the "Mr. Elephant" task (Shusterman et al., 2017) and examined whether children (age 3 to 7 years) succeeded on trials involving quantities 2 and 3. A logistic regression found that Timing and Socioeconomic Status significantly predicted Mr. Elephant performance, while Modality and Age did not. Early-exposed children were more likely to succeed on the task than Later-exposed children. For an exploratory follow-up, two measures of language were added into the analysis: Highest Count, which records children's recitation of the count list, and Give-a-Number ('Give-N'), which assesses children's understanding of the cardinal principle (CP). This logistic regression found that Timing and Give-N performance significantly and independently predicted Mr. Elephant performance, but Socioeconomic Status and Highest Count did not. Children who were CP-knowers were more likely to succeed on Mr. Elephant than non-CP-knowers. These results suggest that the representation of small quantity representations is associated with the timing of children's language exposure and their knowledge of the cardinal principle.