After giving a general introduction (as delineated in the proposal to the thematic section) to the history of the relationship between sociolinguistics and applied linguistics on one hand and psycholinguistics and cognitive neuroscience on the other, this presentation will focus on the central and highly controversial topic of “executive functions” and their relation to bilingualism. It will trace the roots of this concept in politics, organisational studies and computer science, its introduction into neuroscience in 1970’s, its application to frontal lobe dysfunctions in 1980’s and the increasing role it plays in theories of bilingualism and cognition from 1990’s onwards. It will argue, that although the central underlying idea of executive functions is shared by the vast majority of researchers coming from different backgrounds, there are subtle differences in their interpretation, often reflecting the character of the populations (from patients with frontal lobe disorders to mono- and bilingual pupils in schools) and methodologies (from single case studies to factor analyses of large cohorts). These differences, and in particular the contrast between an “executive function” as a unified concept versus a wide range of dissociable “executive functions” as a heterogeneous category become relevant in the context of the “bilingual advantage debate”.