Recent research published in journals Development and psychopathology Our findings suggest that growing up in economically disadvantaged families and neighborhoods tends to be associated with earlier onset of puberty in children. This early biological development provides evidence of a pathway linking lower household income with increased mental health problems and lower academic performance, particularly in adolescent girls.
Scientists know that children who grow up with fewer economic and community resources often have poorer mental health and lower academic performance. However, the precise biological and psychological mechanisms linking lack of resources and these negative outcomes remain unclear. Adolescence is a time of great physical and emotional change, making it a critical time to understand these patterns.
Some scientific models suggest that early life stress, such as financial hardship, may promote physical development. In environments where resources are scarce, the human body may adapt by accelerating reproductive preparation as a survival strategy. Chronic stress due to economic strain or neighborhood disadvantage can disrupt the body’s stress response system, cause irregularities in hormone levels, and cause early onset of puberty.
“Life history theory suggests that economic deprivation may accelerate aspects of development and increase the risk of later mental health problems. We will investigate whether socio-economic disadvantage is associated with earlier onset of puberty and faster pace of brain development, and whether these We wanted to test whether developmental changes could help explain the association between early adversity and mental health risk,” explained study author Divyangana Rakesh, a lecturer in neuroscience and psychology at King’s College London.
To test this idea, scientists had to follow children over several years to see how physical maturation unfolds over time. Previous research has often focused on adolescent development at a single moment in time, rather than tracking the pace of adolescent development over years. Additionally, past research has often confounded different types of economic disadvantage, such as household income and neighborhood quality, which can have different effects on developing children.
Researchers conducted a new study to separate these environmental factors and measure both the onset point and rate of puberty. In doing so, the researchers wanted to understand whether the pace of biological maturation could explain the association between economic hardship and struggles in late teens.
To explore these connections, scientists analyzed information from an ongoing national project called the Adolescent Brain Cognitive Development Study. They focused on a sample of 9,959 children who were approximately 9 or 10 years old at the start of the study. This group was almost evenly divided by gender, with 5,210 men and 4,749 women.
The researchers tracked these children over four time points during the year. They measured household economic stability using a ratio that compares household income to national poverty guidelines. They also assessed neighborhood disadvantage using specialized indicators that looked at local employment, education and housing quality.
To measure pubertal development, scientists used parental surveys that track physical changes such as height growth, hair growth, and skin changes. They looked at both the child’s developmental stage at age 9 and the rate of change in the child over the next three years.
In the second half of the study, researchers collected data on students’ school performance and mental health. The mental health survey asked young people about internalizing problems such as anxiety and depression, externalizing problems such as aggression and rule-breaking, and attention problems.
To ensure the results were accurate, the team considered other factors that may influence puberty and well-being. They adjusted the mathematical model for children’s body mass index, a measure of body fat based on height and weight. We also took into account whether the children had previously experienced a traumatic event, as trauma is independently associated with accelerated physical maturation.
The analysis found that children from more disadvantaged families and regions tend to be more advanced in adolescent development at the age of nine. This pattern emerged for both boys and girls. But as children grew older, researchers found that the rate of physical change in low-income children was actually slower.
For girls, this early onset of adolescence served as a link between economic background and later outcomes. The data suggest that the onset of adolescence as early as age 9 may partly explain why girls from disadvantaged communities and families experience more anxiety and behavioral problems and have lower academic performance by the age of 12.
Delayed developmental progress in subsequent years tended to weaken this connection for the girls. However, researchers believe this may simply be because girls who develop earlier have less room to mature later in the study.
“While lower income predicted earlier onset of puberty, we observed that the tempo of puberty (referring to the rate of change) was slower than expected over time,” Rakesh told SciPost. “Essentially, children from low-income backgrounds tend to start puberty earlier, but the later stages of puberty progressed a little more slowly than expected. This may be because our study started tracking children at age 9, meaning we likely missed an earlier period when development was progressing more quickly.”
Scientists did not find this same connection pathway in boys. Boys from less affluent backgrounds also began puberty earlier, but this early maturation did not directly predict later academic or mental health challenges. Researchers believe this difference may exist because girls are generally exposed to more social pressure and less emotional support when it comes to changing their bodies than boys.
“Lower income was associated with earlier onset of puberty, and earlier onset of puberty predicted a faster pace of brain development,” Rakesh explained. “This suggests that socio-economic conditions may actually shape the pace of biological development.”
There are biological reasons why these conflicts occur during early adolescence. Rapid changes in hormones can cause the brain’s emotional centers to develop much faster than areas responsible for impulse control and decision-making. This discrepancy may make precocious adolescents more sensitive to social stress and more susceptible to risky behaviors that distract from schoolwork.
The researchers pointed out certain misconceptions that readers should avoid when looking at slow rates of development over time. Slower progression later in life does not mean that these children experienced overall developmental delays. Rather, they started puberty so early that their peers only caught up in the later stages of the study.
The scientists also noticed some limitations to their study. Because the study only started observing children at age 9, the researchers likely missed the earliest and quickest stages of adolescence for some participants. Additionally, the observational nature of the study means that scientists cannot definitively prove that financial hardship causes precocious puberty, only that there is a link between the two.
The researchers noted that the effect size found in this study was relatively small for individual children. However, considering the number of children growing up in economically disadvantaged environments provides meaningful evidence at the population level.
Future studies should aim to follow children from an even younger age to understand the complete timeline of physical maturation. Scientists also want to investigate the precise biological processes that drive physical development in humans, such as changes in stress hormones.
“One of the goals is to better identify children who may be at increased risk for mental health problems by understanding how socio-economic disadvantage shapes biological development,” Rakesh said. “In the long term, this could help inform early identification and prevention efforts.”
The study, “Socioeconomic Disadvantage, Adolescent Development, Adolescent Mental Health and Academic Achievement: A Longitudinal Study,” was authored by Kate Fitzsimons, Qingyang Li, Phoebe Thomson, Niamh MacSweeney, and Divyangana Rakesh.
