Growing up bilingual does not disrupt parent–child brain bonding

By Dr. Priyom Bose, Ph.D.Reviewed by Lauren HardakerFeb 23 2026

New hyperscanning research reveals that when bilingual mothers and children play together, their brains align just as strongly in a second language as in their native tongue, challenging assumptions about language barriers in early social development.

Study: The impact of language context on inter-brain synchrony in bilingual families. Image credit: PeopleImages/Shutterstock.com

A recent study in Frontiers in Cognition analyzed spontaneous, child-directed play in both the native and second language to assess how language use shapes neural synchrony.

Unique Features of Bilingual Family Communication

Bilingualism is on the rise, with many families raising children in multilingual settings. These children navigate multiple languages and cultures from an early age, yet they are often overlooked in developmental neuroscience research. This gap restricts our understanding of how bilingualism shapes early cognitive and social development.

Bilingual children develop language and communication skills differently from monolingual peers. They often learn two languages simultaneously, with pace and patterns shaped by their environment. Their combined vocabulary can equal or surpass that of monolinguals, and they show greater metalinguistic awareness, social sensitivity, and executive functioning.

Bilingual parents often acquire the dominant societal language later in life. Even when highly proficient, speaking a second language can feel less natural and alter emotional expression and interaction with their children. These subtle differences can affect communication styles and dynamics, leading to small but meaningful shifts in parent-child interactions.

Bilingual children may also experience emotions and social cues differently depending on the language used. Processing a less dominant language requires more effort, and if either parent or child is less fluent, social coordination becomes more challenging.

Neural Synchrony in Bilingual Parent, Child Communication

To understand bilingual parent-child communication, it is necessary to study neural synchrony, the alignment of brain activity between individuals during shared experiences. Successful communication relies on this neural alignment, which supports language development, social bonding, and cultural learning.

Neural synchrony occurs across social settings, including conversation and joint attention. In parent-child interactions, greater synchrony is linked to stronger emotional connection, engagement, and communication. Synchrony in regions like the prefrontal cortex (PFC) reflects parental sensitivity and child involvement, especially during cooperative activities. Neural synchrony may help children understand caregivers’ intentions and emotions.

Assessing the Role of Language in Neural Synchrony in Bilingual Families

The study investigated whether the language used during mother-child interactions affects neural synchrony in bilingual families. Researchers used near-infrared spectroscopy (fNIRS) hyperscanning to record simultaneous brain activity from mothers and children during natural play. Hyperscanning measures brain activity from multiple individuals simultaneously, capturing how their brains align in real time. A naturalistic free play approach allowed families to interact spontaneously in both languages, providing insight into how everyday language use shapes neural synchrony.

The study focused on the PFC and temporoparietal junction (TPJ), key regions for social thinking and joint attention. Synchrony in these areas is considered fundamental to social connection, enabling partners to share goals and understand each other's intentions during interaction.

A total of fifteen mother-child dyads participated in this study. Mothers in this study had an average age of 38 years and were all non-native English speakers who met a C1 proficiency threshold. Children ranged in age from 3 to nearly 5 years, with no reported sensory, cognitive, or motor impairments. Participants were recruited through local research networks and online parent groups.

Each dyad attended a single session, where they were seated at a child-friendly table, and dyads engaged in naturalistic play with toys such as Mr. Potato Head and building blocks. The fNIRS cap was first fitted to the mother, then to the child, and the relevant data were recorded.

Brain Synchrony Patterns Linked to Play, Not Language or Age

Analysis revealed significant effects of play context and brain region on neural synchrony. Synchrony differed across play conditions and was influenced by the specific child and mother brain regions involved.

Of all possible interactions, only the one between directionality and maternal brain region was significant, suggesting that directionality's effect depended on the specific maternal brain region. No other higher-order interactions reached significance, indicating effects were largely independent.

Pairwise comparisons revealed no significant differences in synchrony across the English interactive, native interactive, or independent play conditions, though interactive play showed numerically higher synchrony than independent play.

To improve sensitivity in comparing interactive and independent play, the two interactive conditions (English and Native) were averaged, as no significant difference was found between them. This combined analysis was exploratory in nature and should be interpreted with caution. Averaging both interactive conditions, neural synchrony was significantly higher during interactive play than during independent play.

Synchrony was higher in the child’s left PFC than in the left TPJ, with no other significant regional differences. For mothers, synchrony was significantly higher in both left and right PFC compared to both TPJ regions, with no difference between left and right PFC or between the TPJ regions. Overall, synchrony was strongest in the PFC for both mothers and children, and lower in TPJ regions.

Child-directed synchrony was higher in English than in the native language, but this difference did not remain significant after permutation testing. No significant relationships were found between the age of either the mother or the child and neural synchrony, though some correlations approached significance and did not meet statistical thresholds.

Conclusions

This study suggests that interactive play, particularly when both interactive conditions were combined in an exploratory analysis, is associated with increased neural synchrony between parents and children, with the strongest effects observed in the PFC. The findings suggest that the interaction context, rather than the specific language spoken, plays a larger role in shaping brain-to-brain alignment than participant age in this sample.

Future research should explore how different types of interaction and family backgrounds influence neural synchrony. Expanding the participant pool and examining other cultural or linguistic contexts will help clarify how social dynamics shape parent-child brain connectivity.

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