Do you know the answers? Japanese and Hungarian preschoolers’ response tendencies to comprehensible and incomprehensible yes-no questions

We investigated Japanese and Hungarian children’s response tendencies to comprehensible and incomprehensible yes-no questions about objects. We found that 2-year-old children exhibited a strong and consistent yes bias to all questions, 3-year-old children tended to exhibit a yes bias to comprehensible questions, and children aged 5 and 6 exhibited a nay-saying bias to incomprehensible questions. Moreover, both Japanese and Hungarian children aged 5 and 6 demonstrated an instruction effect (i.e., responded with “I don’t know” when told this was an acceptable response). We discuss the possibility that older children exhibit a nay-saying bias or respond with “I don’t know” due to their developed meta-cognitive and meta-linguistic knowledge.