The effect of biculturalism on executive functions

Much debate in the field of bilingualism has centred around a bilingual’s advantage in Executive Functions (For a recent review, see Lehtonen et al., 2018). In light of recent conflicting evidence regarding the premise of a bilingual advantage, scholars have begun to scrutinize possible variables and confounds arising from differences in the broader social and interactional environment (de Bruin, 2019). While variables such as proficiency, immigration, and age of acquisition have received much attention over the years, there is still a paucity of research into culture as a variable exerting an effect on bilingualism. To the best of our knowledge, the few studies considering the impact of culture on bilingual’s Executives Functions group participants on the macro-level culture that is commonly associated with their nationality (e.g. Samuel, Roehr-Brackin, Pak,& Kim, 2018; Tran, Arredondo,& Yoshida, 2015). Yet, this does not capture a sufficiently nuanced perspective of the cultural diversity among bilingual populations (Grosjean, 2015). This thesis is the first to explore the effects of biculturalism on Executive Functions among bicultural-bilinguals. Study 1 surveyed 252 bilingual Singaporean young adults to provide an overview of how they viewed language and their ethnic cultural identities. The results show that the majority of Singaporean young adults (71.7%) were bicultural. The likelihood of biculturalism was predicted by their ethnic language proficiency and bilingual status (Balanced vs. Unbalanced). To augment the self-report data in the first study, Study 2 integrates self-report questionnaire data on cultural and language behaviour with a priming experiment (cultural frame switching, adapted from Hong, Morris, Chiu,& Benet-Martinez,2000) to provide empirical evidence of bilingual Singaporean young adults ability to switch between cultural frames. 233 participants from Study 1 continued with this follow up study, and the results suggest that Singaporean young adults were not only bicultural but were also able to switch between different cultures when primed with Western and ethnic cultural primes. Individuals who switched between cultural frames more frequently made a clearer distinction between Western primes than those who switched between cultural frames less frequently, suggesting that cultural primes impact cognition differentially depending on their frequency of switching between cultures. Study 3 explored the effect of cultural switching frequency on 48 young adult bicultural bilinguals’ performance on tests for interference and inhibition-control (Simon and Flanker tasks), set-shifting ability (Wisconsin Card Sort Task), and attention (Attention Network Task). Frequent cultural switchers had an advantage in resolving stimulus-response conflict significantly faster in the Flanker task, were better at maintaining set in the Wisconsin Card Sort Task, and had a smaller CONFLICT effect compared to infrequent switchers in the Attention Network Task. Taken together, this thesis has implications for future studies of bilingual populations, as the bicultural switching effects on interference and inhibition-control persists even after tightly controlling for key socio-linguistic variables including bilingual proficiency, age of acquisition, IQ, socio-economic status and age. Our research underscores the importance of considering socio-cultural variables in future studies examining a bilingual advantage in Executive Functions.Master of Art