Victoria Leong

Most studies regarding the relationship between multilingualism and cognitive control reduce linguistic diversity to a dichotomous comparison, viz., monolinguals vs. bilinguals, failing to capture the multifactorial nature of multilingualism. Language research is largely restricted to the Global North, albeit most of the world’s population resides in the Global South, limiting the interpretability of the existing literature. Cognitive performance is assessed using very few tasks, yielding unreliable measurements. In this study, we identify the manner in which multilingual experiences influence cognitive performance in diverse sociolinguistic contexts. Young adults from the UK (n = 51, mean age = 24.0, SD = 3.18) and Singapore (n = 36, mean age = 21.3, SD = 2.15) were tested using an extensive battery of cognitive tasks, including cognitive flexibility (CF), working memory (WM), inhibition, and structure learning (SL). Information on language proficiency, use, age of acquisition, and frequency of switching was collected. The effects of various linguistic factors on the cognitive performance of each group were assessed using multiple linear regression models. The UK and Singapore samples exhibited significantly different linguistic profiles, which in turn dissimilarly influenced their cognitive performance. Our study underscores the necessity for more research in the Global South, challenging the prevailing Northern-centric focus on the multilingualism–cognition relationship.

While mother–infant affect synchrony has been proposed to facilitate the early development of social understanding, most investigations into affect synchrony have concentrated more on negative than positive affect. We analysed affect sharing during parent–infant object play, comparing positive and negative affect, to examine how it is modulated by shared playful activity. Mother–infant dyads ( N = 20, average infant age 10.7 months) played together (social) or separately (solo) using an object. Both participants increased positive affect during social play as compared with solo play. Positive affect synchrony also increased during social play compared with solo play, whereas negative affect synchrony did not differ. Closer examination of the temporal dynamics of affect changes showed that infants' shifts to positive affect tended to occur contingently in response to their mothers', whereas mothers’ shifts to negative affect followed their infants'. Further, during social play, positive affect displays were more long-lived while negative more short-lived. While our sample was small and from a homogeneous population (e.g. white, highly educated parents), limiting the implications of the findings, these results demonstrate that maternal active engagement in playful interaction with her infant affords, increases, and extends infant positive affect and parent–infant positive affect synchrony, providing insights into how the social context modulates infants’ affective experiences. This article is part of a discussion meeting issue ‘Face2face: advancing the science of social interaction’.