Long-Term Impacts of Low Language Proficiency in Children on Literacy and Well-being

Children with low language proficiency (LLP) between ages four and eight are likely to experience long-term difficulties with literacy and language as they grow older, according to a meta-analysis of 80 studies involving approximately 28,800 children in North America and Europe. The evidence, updated to March 2025, also indicates higher risks for mental health problems and social difficulties.

How does low language proficiency affect children as they grow?

Children with LLP face consistent difficulties with literacy—the ability to read—as they reach adolescence and adulthood. Researchers expressed high confidence in this finding based on the analyzed data.

Language difficulties also tend to persist, though researchers reported moderate confidence in this outcome because some participants dropped out of the studies. For some children, these early challenges improve over time, while for others, they continue to hinder learning and communication.

Did You Know? The findings are based on a meta-analysis of 15 different cohorts of children across North America and Europe, totaling roughly 28,800 individuals.

What are the psychological and social risks of LLP?

Children with low language skills are at a higher risk for mental health problems, specifically depression and anxiety, according to the review. These children also frequently encounter difficulties making friends.

Researchers found moderate confidence regarding these psychological outcomes and a lack of participation in everyday life. They noted that variation between studies and small sample sizes for participation data affected the confidence level of these results.

Expert Insight: Samantha Carter notes that the contrast in confidence levels is significant. While the link between early language struggles and later literacy is firmly established, the connection to broader quality-of-life outcomes remains more volatile and subject to change as more data emerges.

Where is the evidence limited regarding adult outcomes?

Current evidence is insufficient to determine if LLP affects physical health. Researchers stated they are not confident in any link between early language proficiency and later physical health outcomes.

Samantha Carter Introduction Speech (SPCH-1311-101)

Confidence is also low regarding whether early language skills affect a person’s ability to become independent. Because very few studies reported on independence, researchers indicated that further evidence is likely to change current results.

What is needed to better understand these outcomes?

The review concludes that more long-term, high-quality studies are necessary to clarify how LLP affects independence and daily participation. These studies would require larger samples and comparison groups.

Because results varied between studies, researchers noted that not all children with LLP are affected in the same way. Factors such as other health conditions or non-verbal IQ were not always reported, leaving gaps in the current understanding.

Frequently Asked Questions

What is low language proficiency (LLP)?
LLP refers to children who have difficulties speaking, understanding, or using language in early childhood, often identified through clinical diagnosis or scoring below average on language tests.

Which long-term outcome has the strongest evidence?
Researchers are highly confident that children with LLP experience difficulties with literacy, or the ability to read, as they grow up.

Does LLP lead to physical health problems?
The evidence is very uncertain, and researchers are not confident that children with LLP have difficulties with physical health in adulthood.

How can early identification of language difficulties change the trajectory for a child’s adult life?