Abstract
The performance of cognitive tests is highly dependent on the proficiency of the language in which the tests are administered. Not all Indonesians speak Indonesian daily and many are bilingual. We investigate whether language(s) spoken affects the performance on three language tests in 840 participants ranging in age (16-80) and education (6-22 years). Analysis of covariance followed by Helmert contrasts showed a disadvantage on the Boston Naming Test (BNT) and on the most difficult items of the Token Test for those who do not speak Bahasa daily. Bilinguals did worse on the BNT. Education had a large positive effect on the language tests, age a smaller negative effect. This suggests that besides age and education, the factor of language spoken, either in public or at home, needs to be taken into account when a participant's test scores on the BNT and TT are interpreted and compared with normative data.
