Understanding the Link Between Socioeconomic Status and Reading Skills
Children from families with higher parental education often show stronger reading abilities. A recent study has revealed that this connection is largely due to differences in oral language skills rather than structural brain differences. Published in Developmental Cognitive Neuroscience, the research highlights how language exposure and vocabulary development play a crucial role in bridging the gap between socioeconomic background and reading success.
For years, researchers have observed that children from higher socioeconomic backgrounds tend to perform better in reading. This trend is particularly evident when measuring socioeconomic status through parental education, which is a stable indicator. While earlier studies have shown that lower parental education correlates with weaker reading skills and reduced brain connectivity in areas related to reading, the exact mechanisms behind these links were unclear.
The current study aimed to clarify these relationships by examining whether white matter integrity—measuring brain connectivity—directly or indirectly influences the link between socioeconomic status and reading performance. It also explored how various oral language skills might mediate this connection. The goal was to determine if brain structure, language ability, or both contribute to how socioeconomic background affects reading outcomes.
"Reading is a critical skill that impacts educational attainment, employment, and overall quality of life," said Martina Villa, a graduate student at the University of Connecticut and the study's author. "Understanding how we develop reading abilities and what factors contribute to their success is essential. Previous studies have identified environmental and neural influences, but now we need to understand how they interrelate."
The researchers used data from the Healthy Brain Network, a large biobank of children and adolescents aged 6 to 15. After applying exclusion criteria, the final sample included over 3,000 participants, with more than 800 having complete data on brain imaging, language skills, and reading assessments.
Participants completed standardized assessments to measure different aspects of language and reading ability. Key areas included phonological awareness, which refers to the ability to recognize and manipulate sounds in spoken language. Vocabulary, or the number of words a child understands and can define, was another focus. Reading fluency, which measures how quickly and accurately a child can read written words, was also tested.
Together, phonological awareness and vocabulary were considered components of oral language—a broader category that includes all aspects of spoken language ability. Oral language development typically begins before formal reading instruction and plays a key role in learning to read.
To understand how these variables interacted, the researchers used structural equation modeling, a statistical method that allows for the testing of complex relationships among multiple variables.
The findings showed that socioeconomic status predicted reading skill, but the pathway linking these two factors ran through oral language, not brain structure. Children with more highly educated parents tended to have stronger phonological awareness and larger vocabularies, which were strongly linked to better reading performance.
In contrast, white matter integrity did not appear to play a significant role in explaining the association between socioeconomic status and reading. While higher parental education was associated with slightly higher white matter integrity in some tracts, those differences did not predict reading ability. In other words, the structural properties of these brain pathways did not mediate the connection between socioeconomic status and reading.
The researchers were surprised by the lack of a strong relationship between white matter and reading skill. "Prior evidence for the tracts we selected is quite robust, and I thought we would replicate those findings, even with a larger and more diverse sample," Villa said. "This shows how powerful sampling biases can be when studying small effects, and how careful we should be in generalizing research findings."
The models confirmed that oral language skills acted as reliable mediators. Phonological awareness had a strong influence on reading, while vocabulary contributed to a lesser extent. These findings remained consistent across all three brain imaging models and after adjusting for participant age and brain scan quality.
Follow-up analyses found no significant evidence that age altered the strength of the relationship between socioeconomic status and reading, suggesting that the effect of parental education on reading outcomes remained relatively constant from ages 6 to 15.
Although the main pathway from socioeconomic status to reading did not involve brain structure, the study detected small but consistent associations between parental education and white matter integrity in some brain regions. These associations were especially noticeable with advanced imaging methods.
In one model, higher parental education was linked to greater fiber density in all nine white matter tracts examined. However, these structural differences were not significantly related to reading performance. Only one specific tract—the left inferior longitudinal fasciculus—showed a weak link to reading ability, and even that association did not hold up across all models.
The study also found that some white matter tracts were linked to oral language skills. For example, in one model, white matter structure in the left superior longitudinal fasciculus and arcuate fasciculus predicted vocabulary scores. Another model found that the left inferior longitudinal fasciculus was associated with phonological awareness. Still, these associations were modest and did not form part of a broader chain connecting socioeconomic status to reading.
Villa outlined three main takeaways: (1) While genetics may predispose individuals to reading proficiency, environmental factors like parental education should not be overlooked; (2) Oral language skills, such as vocabulary, are important in developing reading skills; and (3) While anatomic connections between key reading areas do not mediate the effects of parental education on reading, other influences may exist, possibly earlier in development.
Despite its strengths, the study has limitations. The data were cross-sectional, meaning measurements were taken at one point in time, so the researchers could not determine if changes in brain structure or language skills caused improvements in reading. The study also did not explore other potential pathways from socioeconomic status to reading, such as parenting style, school quality, or access to learning resources.
While the researchers used advanced imaging techniques, white matter integrity remains a complex and indirect measure of brain function. Future studies using functional brain activity or higher-resolution scans may uncover other neural features that explain reading disparities across socioeconomic groups.
Another limitation relates to the sample itself. Although the sample was larger and more diverse than most neuroimaging studies, it still skewed toward families with higher levels of education. Future studies including more low-income participants may provide a clearer understanding of how early life experiences shape brain development and literacy.