Unity and diversity of the executive functions in early adolescents from Iran: alternative factor structures and invariance across age and socioeconomic status

Executive functions (EFs) are cognitive skills that regulate thoughts and behavior. The unity and diversity model of EF, one of the most prominent frameworks in this field, proposes the existence of three correlated but separable EF domains (inhibition, updating and switching). This fractionation of EF has been shown from adolescence on in some, but not all studies, which usually only reported a few of many possible factor structures. Additionally, age and socioeconomic status (SES) effects in these studies were unreliable due to lack of invariance testing, necessary to ensure that participants of different ages/SES perform tasks similarly so that these effects can be estimated. Hence, we tested this framework in 407 9-15-year-old Iranians of variable SES using a test battery that includes two tasks for each EF domain and allows cultural adaptations regarding language and stimuli. We tested various alternative model configurations (one, two and three factor, nested and bifactor-S-1 models) using Confirmatory Factor Analyses and, for the selected best fitting model, performed invariance testing (across age and SES) with Multiple Indicators, Multiple Causes model. The best fitting model solution (three-correlated factors) replicated prior results in early adolescent samples from different countries, speaking to the universality of the separability of the three EF domains at this age. Furthermore, this model exhibited differential item functioning for only one of 7 indicators (for age and SES) allowing us to reliably show that all three EF latent traits improve with age, while SES exerts only minimal positive effects on shifting and updating

Fractionation of executive functions in adolescents from Iran: invariance across age and socioeconomic status

Executive functions (EFs) are cognitive skills that regulate thoughts and behavior. The seminal EF unity and diversity theoretical framework proposes the existence of three correlated EF latent domains (inhibition, updating, and switching) that become distinguishable from a certain moment during adolescence, but it is unclear how age and socioeconomic status (SES) afect these abilities. Here, we assessed 407 9-15-year-old Iranians of variable SES using an open-access battery of executive function tests that includes two tasks of each EF domain and allows for sociocultural adaptations regarding language and stimuli. Various EF model confgurations proposed in the literature were tested (one, two and three EF latent factor, nested and bifactor-S-1 models) using confrmatory factor analyses. In addition, to explore the unbiased efects of age and SES, we performed invariance testing (across age and SES) using multiple indicators multiple causes (MIMIC) model to the best ftting model solution. The three-correlated EF factor model had the best ft and was mostly invariant across age and SES, with all three EF latent traits improving with age, while SES exerted only minimal positive efects on shifting and updating. We concluded that the three separable EF domains, found in adults and adolescents of other ages from diferent populations, can already be detected from the beginning of adolescence when culturally and psychometrically appropriate EF tasks are used. Additionally, these abilities continue to improve with age and are little afected by SES, suggesting that the unity and diversity framework is useful to study the cross-country generality of EF development.publishedVersio