Orientation: The use of personality tests for selection and screening has been consistently criticised resulting from the risk of socially desirable responding amongst job applicants. Research purpose: This study examined the magnitude of culture and language group meanscore differences amongst job applicants and the moderating effect of race on the relationship between social desirability and cognitive ability. Motivation for the study: The influence of cognitive ability and potential race and ethnic group differences in social desirability scale scores, which can lead to disproportional selection ratios, has not been extensively researched in South Africa. Research design, approach and method: A quantitative, cross-sectional research design, based on secondary datasets obtained from the test publisher, was employed. The dataset consisted of 1640 job applicants across industry sectors. Main findings: Moderated multiple regression analyses revealed that the relationship between social desirability and general reasoning was moderated by culture and language, with group differences in social desirability being more pronounced at the low general reasoning level. This suggests that social desirability scales may be an ambiguous indicator of faking as the scales may indicate tendency to fake, but not the ability to fake, that is likely to be connected to the level of cognitive ability of the respondent. Practical/managerial implications: Individual differences in social desirability are not fully explained by cognitive ability as cultural differences also played a role. Responding in a certain manner, reflects a level of psychological sophistication that is informed by the level of education and socio-economic status. In relation to selection practice, this study provided evidence of the potentially adverse consequences of using social desirability scales to detect response distortion. Contribution/value-add: The exploration of cross-cultural differences in the application of social desirability scales and the influence of cognitive ability is seen as a major contribution, supported by possible explanations for the differences observed and recommendations regarding the practice of universal corrections and adjustments.