Executive functions in Thai adolescents: Development of an inventory measure, its factors, and norms

Thai researchers developed a new self-report measure of executive functions for adolescents based on Diamond's framework (the Behavioral Inventory Measure of Executive Functions [BIMEFs]). How it was developed, its psychometric properties, and norms by sex and age are reported here.

An independent panel of experts evaluated the content validity of BIMEFs. Reliability was checked using Cronbach's alpha with a sample of 45 secondary students. 1,865 students, ages 12 - 18 years (65% female) from across Thailand participated in the normative study.

The BIMEFs consists of 42 items that assess inhibitory control (IC), working memory (WM), and cognitive flexibility (CF), including eight subcomponents. For all items, the index of item-objective congruence was >0.5 and Cronbach's alpha was >0.7. Confirmatory factor analysis (CFA) showed the adjusted goodness of fit index to be 0.9. The strongest sex difference was for IC. Students of 13 years scored lower on EFs overall, IC, WM, CF, and all subcomponents than older students. Self-control, verbal working memory, and being able to change perspectives showed the most pronounced differences by age.

The BIMEFs, which is designed to be culturally-appropriate for Thailand and cross-culturally generally, is the first EF questionnaire based on Diamond's framework. It shows good psychometric properties and sensitivity to age and sex differences. It indicates that IC development, at least in Thailand, plateaus earlier than WM and CF and that CF shows a more protracted development during adolescence than IC or WM.