Research on a large sample of five- to seven-year-olds in the USA has shown that bilingualism supports early cognitive development and protects children from the damaging influence of poverty.
The researchers recommend that structured language immersion and bilingual education become an important part of work with disadvantaged families.
The science: bilingualism, executive function and cognitive development
Executive function [link to cognitive development theory fact article], a foundation for strong cognitive development, is a set of mental skills that help us get things done. Scientists have identified four components:
- Working memory – the ability to hold information and recall it when carrying out a task.
- Inhibitory control – suppressing initial impulses in favour of more rational action.
- Attentional flexibility – changing from one way of solving a problem to another.
- Planning – using all the skills above and creating a strategy to get a task done.
Children who score highly on measures of these components are likely to be more ready for school, to achieve more in education, and to have better physical health and social skills.
Poverty has been shown to inhibit the development of executive function skills. Children from well-off families have more and better material resources and more social connections and they experience more positive parenting. All these things boost their social and cognitive development.
Research has also shown a positive correlation between bilingualism and cognitive development, especially executive function. Bilingualism supports skills that are specific to executive function: careful attention to the target language, suppressing the non-target language and effectively switching between languages.
In this study, four aspects of executive function were measured four times in children in kindergarten and first grade, that is, five- to seven-year-olds.
- Inhibition and shifting. Children were given 22 cards of red and blue boats and rabbits, some with a border around the edge. They were asked to sort the cards in three different ways – by colour, object and by border.
- Working memory. Children were asked to repeat backwards a series of numbers spoken to them.
- Inhibitory control. Teachers were asked to rate the children’s behavior, for example, by answering prompts such as “The child can wait before entering into new activities if he/she is asked to.”
- Attentional focusing. Teachers were asked to rate the children’s behavior, for example, by answering prompts such as “When building or putting something together, the child becomes very involved in what he/she is doing, and works for long periods.”
A measure for socioeconomic status covered household income and the education and occupation of the mother and father.
Findings: bilingualism mitigates the negative impact of low socioeconomic status
Earlier studies with smaller samples have shown that bilingualism does not reliably influence cognitive development via executive function. This study, with a much larger sample, found the opposite.
In line with earlier research, lower socioeconomic status was found to inhibit cognitive development. Children from disadvantaged backgrounds performed less well on all the measures. Meanwhile, being bilingual improved performance on all four tests. (Though, in the test of reciting numbers backwards, it did so only for the older children. This might be because the task required specific linguistic skills which develop a bit more slowly in bilingual children.)
The study’s core finding was that poverty’s negative influence on cognitive development was smaller for bilingual children. Similarly, bilingualism made a bigger positive difference on measures of executive function among children from more disadvantaged families.
The findings held true irrespective of gender, culture and language proficiency.
Implications for child cognitive development policy
This research suggests that bilingualism contributes specifically to cognitive development in young children who are starting out in school, as measured by executive function skills. Meanwhile, executive function skills are associated with better school readiness, higher achievement in education, better physical health and better social skills. This suggests a link between early bilingualism, strong cognitive development and later life achievement.
Moreover, the research shows that bilingualism’s benefit to cognitive development is particularly apparent in children with fewer resources at home. Thus the researchers recommend structured language immersion and bilingual education for children of disadvantaged families.
Hartanto A, Toh WX & Yang H (2018), Bilingualism narrows socioeconomic disparities in executive functions and self‐regulatory behaviors during early childhood: evidence from the Early Childhood Longitudinal Study, Child Development