The plural still counts: Cross-linguistic study of the symbolic numerical magnitude comparison task in Polish- and German-speaking preschoolers
Already in toddlerhood, children begin to master the system of number word meanings. The role of grammar, and in particular grammatical number inflection, in early stage of this process has been well documented. It is not clear, however, whether the influence of the grammatical language structure also extends to more complex later stages. In the current study, we have addressed this problem by using differences in the grammatical number paradigms between Polish and German, in particular, the inconsistency of the grammatical number of the verb and the noun for numbers above four. One-hundred-fifty-three Polish-speaking children and 124 German-speaking three-to-six-year-old children took part in the study. Their main task was to compare symbolic numbers (Arabic numerals and spoken number-words) in the range of small numbers (2-4) large numbers (5-9) and between ranges. In addition, counting skills (Give-a-number and count-list) and mapping between non-symbolic (dot sets) and symbolic representations of numbers were checked. The children also performed working memory tests (Corsi-blocks and digit span). Based on Give-a-number and mapping tasks, participants were divided into subset-knowers, CP-knowers-non-mappers and CP-knowers-mappers (cf. LeCorre, 2014). As expected, grammatical number structure influenced performance: Polish-speaking children, later than the German ones, achieved the CP-knowers stage and, after it was achieved, they fared worse in the numerical comparison task, which was further mediated by response side. Importantly, however, there were no significant differences in the mapping task between non-symbolic and symbolic representations of numbers between Polish and German groups. We conclude that cross-linguistic differences in the grammatical number paradigms can significantly affect the development of representations and processing of numbers not only at the stage of acquiring the meaning of the first number-words, but also at later stages, when dealing with symbolic numbers.