ISSN : 1229-0718
The present experiment tested whether 5- and 9-year-old children and adults have a cognitive bias to misinterpret the class-inclusion relations as the part-whole relations of collections when only minimal information about a hierarchical relation was given. Novel and familiar class-inclusion relations were taught using drawings of novel and familiar objects that were referred to by nonsense syllables. In all three age groups of subjects, the errors occurred almost exclusively on the upper level of hierarchy and most of the errors were to misinterpret class-inclusion relations as the part-whole relations of collections. In addition, 5- and 9-year-old children made more errors than adults on the upper level of hierarchy but not on the lower level. The results demonstrated that children and even the college students have a bias to misinterpret class-inclusion relations as the part-whole relations of collections, even though the latter have the bias in a much lesser degree.