Executive Functions (EFs) encompass cognitive skills that are responsible for regulating cognition, thoughts and behavior. EFs develop in adolescence and are associated with mental and physical health outcomes. One of the most accepted models of EF is the unity and diversity model, which proposes the existence of three correlated but separable domains (Inhibition, Updating and Shifting). Evidence of this model from culturally diverse samples is still lacking even though EFs are influenced by contextual/cultural factors. Our objective was to test this model in adolescents from non-WEIRD (western, educated, industrialized, rich and democratic) countries, Brazil and Iran. The test battery was developed to be culturally adaptable (Free Research Executive Evaluation battery: FREE) and included two tasks of each EF domain. Models with one, two and three factors (including a nested factor) were tested with Confirmatory Factor Analysis in 739 9-15 year-olds (407 Iranians; 358 girls). The best fitting model solution for countries analyzed separately (three-correlated factors) was used for multi-group invariance testing (configural, metric, scalar) across sex and country, and differential item functioning (multiple indicators - multiple causes: MIMIC) across age and socioeconomic status (SES). Configural, metric and scalar invariance were found for sex and country (except for only partial scalar invariance for country). The model was also invariant across SES and age (except that one task showed differential item functioning per age). We conclude that the culturally adapted FREE battery yielded reliable factor constructs in adolescents across-nations, making it potentially useful to explore universal aspects of EF at this age.
