Bilingualism and executive functioning
: Language experience as more than a binary variable.

  • Emma Jenks

Student thesis: Doctoral ThesisDoctor of Philosophy


The possibility of bilingual advantages in executive functioning has been a matter of debate for some time. One side of the argument claims that certain bilingual experiences lead to practice and therefore improvement in executive control. Others draw attention to a possible publication bias, a recent series of null results and the large-scale variance within bilingual populations.

The current work sought to further examine the bilingual advantage and the circumstances under which it may become apparent. Bilingual and monolingual performance on a series of inhibitory control and set shifting tasks, including a novel response switching task, were compared across four studies. Emphasis has been placed on the importance of bilingual background variables, such as 2nd language ability and age of acquisition, and these were included alongside multiple measures of daily language switching habits and linguistic distance.

Results were largely null, with some monolingual advantages becoming apparent in stop signal and colour shape tasks. There was no conclusive evidence for advantages related to frequent switching or linguistic distance. The use of a 2nd language within a dual language context, as described by the Adaptive Control Hypothesis, did not have a significant effect on bilingual performance compared to monolinguals.

The results of these studies are then discussed within the context of a changing research landscape, where it is becoming apparent that bilingualism does not consist of a single, straightforward variable. Researchers are beginning to treat bilingualism with more nuance than early studies and the field is becoming more accepting of null results, allowing for a bigger picture to emerge.
Date of AwardJul 2022
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SponsorsNorthern Ireland Department for the Economy
SupervisorTim Fosker (Supervisor) & Judith Wylie (Supervisor)


  • Executive function
  • bilingualism
  • bilingual advantage
  • task switiching

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