Cognitive difficulties are very common in children from impoverished backgrounds, putting them at risk of educational failure. However, it is not clear what influences the development of cognitive abilities, nor when such factors have their biggest impact. What is more important, your parent’s degree or the town you grew up in?
This issue was addressed in a recent paper by University of Pittsburgh child psychiatrist Daniel Hackman and his colleagues. They found that parental education, but not the characteristics of a neighbourhood, was associated with working memory performance.
Understanding working memory
Working memory is one of the most important cognitive abilities for learning. This system allows us to juggle multiple thoughts simultaneously. It is at the heart of intellectual functioning, playing a crucial role in many everyday activities from following directions to understanding what we read.
Working memory has a “limited capacity”. This means that there is an upper limit to the amount of information we can hold in our minds at any given time. Working memory capacity varies greatly between individuals. In kids it is a strong predictor of many cognitive functions such as reading and maths skills. Early on in life, working memory abilities are closely linked with school grades. Children with bigger working memory capacities typically perform better in the classroom.
Deficits in working memory are very common in children from underprivileged backgrounds and place them at increased risk of poor progress at school. Children from deprived families therefore face both social and economic barriers to success and impaired cognitive skills. This means that they are often ill-equipped to overcome hardship and break out of the vicious circle of poverty.
The link between social background and cognitive ability is present in babies as young as four months and adults over 50. However, it is not clear whether poverty predicts how cognitive skills develop and change as we get older. Nor do we know how different socio-economic factors, such as postcode or family income, affect these changes.
Working memory development
Hackman’s team was the first to conduct a longitudinal study to investigate the development of working memory over time. The authors set out to understand when social status impacts on working memory and how working memory changes as children grow up.
They focused on two measures of socio-economic status. These were family environment, indexed by parents’ education, and wider social context. Social context was defined by neighbourhood characteristics, such as the number of people below the poverty line or unemployed.
Authors speculated that differences in working memory would change between childhood and adolescence in three possible ways. They might grow as the effects of poverty build up, further disadvantaging children from deprived families. They might remain constant, reflecting early emerging differences but similar developmental pathways. Or, the differences might diminish as the children mature into adolescence.
In this study a group of more than 300 10 to 13-year-olds was followed over the course of four years. Each year children completed a set of working memory tests. Socio-economic status was measured using demographic questionnaires and census records for the child’s home address. Parent’s level of education in years was also recorded.
The results showed that parents’ level of education, but not neighbourhood characteristics, was associated with working memory skills. Because working memory is closely linked to learning, this means that parental education is likely to be a good predictor of their kids’ academic success. In a way, children with better educated parents, and not those living in affluent areas, are more likely to excel at school.
Importantly, this study showed that differences in working memory related to parental education were apparent in early childhood and remained stable over time. This means that children who had smaller working memory capacities at the beginning of the study (linked to their parents’ schooling) did not catch up with the children of better educated parents. Their working memory capacities grew at the same rate as children of better educated parents as they got older. However, the gap between children from homes where parents had an average of 12 years of education and those from homes where parents had an average of 16 years of education was the same at all ages.
Training working memory
The early onset and apparent persistence of poverty-driven deficits in working memory emphasises the need for early intervention. Boosting working memory is important for enhancing learning to promote positive life outcomes and overcome hardship.
One way we can improve working memory is by using computerised “brain-training” programmes. These typically involve repeated practice on increasingly challenging cognitive tasks. Such programmes have already been used to enhance working memory in children and adults.
Perhaps one way forward is to use cognitive training as a preventative intervention with very young children from impoverished backgrounds. Although this is unlikely to improve cognitive function in the same way as rich childhood experiences do, it may help to compensate for the damaging effects of early adversity on working memory.