Abstract
This study tests the universality of the Western-based concept known as cognitive age within Japan. It assesses both the internal and external validity of cognitive age among Japanese seniors and compares the findings to the same measures of cognitive age with a sample of senior respondents from the United States. The study finds that the semantic differential scale has the largest trait variance among all aging concepts studied (average cognitive age, average ideal age, and average least-desired age), while the Likert scale possesses the largest trait variance for average cognitive age. The ratio scale was found to have the lowest trait variance of the three scaling formats evaluated. External construct validation studies revealed a remarkable similarity between Japanese females and males, and contrasts between Japanese and American seniors revealed reasonably good generalizability between countries. Average cognitive age appears to be universal within two culturally disjoint countries (the United States and Japan), yet the efficacy of individual measurement scales varies between them.