Early puberty provides a biological link between childhood economic disadvantage and teenage emotional struggles in girls

A recent study published in the journal Development and Psychopathology suggests that growing up in financially disadvantaged households or neighborhoods tends to be linked to an earlier onset of puberty in children. This earlier biological development provides evidence for a pathway that connects lower family income to increased mental health challenges and lower school grades, particularly in adolescent girls.

Scientists know that children growing up with fewer financial and community resources often experience worse mental health and lower academic achievement. However, the exact biological and psychological mechanisms that connect a lack of resources to these negative outcomes remain somewhat unclear. Adolescence is a period of massive physical and emotional change, making it a highly relevant window for understanding these patterns.

Some scientific models suggest that early life stress, such as economic hardship, might speed up physical development. In environments where resources are scarce, the human body might adapt by accelerating reproductive readiness as a survival strategy. Chronic stress from financial strain or neighborhood disadvantage can disrupt the body’s stress response system, leading to irregular hormone levels that trigger an earlier start to puberty.

“Life history theory suggests that financial scarcity can accelerate aspects of development, which may increase risk for later mental health problems. We wanted to test whether socioeconomic disadvantage is associated with earlier pubertal onset and a faster pace of brain development, and whether these developmental changes might help explain links 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 needed to track children over several years to see how physical maturation unfolds over time. Previous research often looked at pubertal development at a single moment rather than tracking its pace over years. Past studies also frequently mixed up different types of economic disadvantage, such as household income and neighborhood quality, which can have different effects on a developing child.

The researchers conducted the new study to separate those environmental factors and measure both the starting point and the speed of puberty. By doing so, they hoped to understand if the pace of biological maturation explains the link between economic hardship and later teenage struggles.

To explore these connections, the 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 around nine or ten years old at the start of the research. The group was roughly evenly split by sex, including 5,210 males and 4,749 females.

The researchers tracked these children across four annual time points. They measured household financial stability using a ratio that compares family income to national poverty guidelines. They also assessed neighborhood disadvantage using a specialized index that looks at local employment, education, and housing quality.

To measure pubertal development, the scientists used parent surveys that tracked physical changes like height spurts, body hair growth, and skin changes. They looked at both the children’s developmental stage at age nine and the rate at which they changed over the next three years.

Later in the study, the researchers collected data on the students’ school grades and their mental health. The mental health surveys asked the youths about internalizing issues like anxiety and depression, externalizing issues like aggression and rule-breaking, and attention problems.

To ensure their results were accurate, the team accounted for other factors that might influence puberty and well-being. They adjusted their mathematical models for the children’s body mass index, which is a measure of body fat based on height and weight. They also factored in whether the children had experienced prior traumatic events, since trauma is independently linked to faster physical maturation.

The analysis revealed that children from more disadvantaged households and neighborhoods tended to be further along in their pubertal development at age nine. This pattern appeared in both boys and girls. However, as the children grew older, the researchers noticed that the rate of physical change was actually slower for those from lower-income backgrounds.

For girls, this early start to puberty served as a connecting link between their economic background and their later outcomes. The data suggests that starting puberty earlier at age nine partly explained why girls from disadvantaged neighborhoods and households experienced more anxiety, more behavioral issues, and lower school grades by age twelve.

Slower developmental progress in the following years tended to weaken this connection for girls. However, the researchers suspect this may simply be because girls who developed early had less maturing left to do in the later years of the study.

“Although lower income predicted earlier pubertal onset, we observed a slower pubertal tempo (which refers to the rate of change) over time than expected,” Rakesh told PsyPost. “Essentially, although children from lower-income backgrounds tended to start puberty earlier, the later stages of puberty progressed a bit more slowly than expected. This may be because our study began following children at age 9, meaning we likely missed an earlier period when development was moving more quickly.”

The scientists did not find this same connecting pathway for boys. While boys from less wealthy backgrounds also started puberty earlier, this early maturation did not directly predict their later academic or mental health challenges. The researchers suspect this difference might exist because girls generally face more social pressure and receive less emotional support regarding body changes compared to boys.

“Lower income was associated with earlier onset of puberty, and earlier puberty in turn predicted a faster pace of brain development,” Rakesh explained. “This suggests that socioeconomic conditions can indeed shape the pace of biological development.”

There are biological reasons why early puberty might lead to these struggles. Rapid hormonal changes can cause the emotional centers of the brain to develop much faster than the areas responsible for impulse control and decision making. This mismatch can make early-maturing adolescents more sensitive to social stress and more prone to risky behaviors that distract from schoolwork.

The researchers pointed out a specific misinterpretation that readers should avoid when looking at the slower rate of development over time. A slower progression in later years does not mean these children experienced delayed development overall. Instead, because they started puberty earlier, their peers were simply catching up during the later stages of the study.

The scientists also noted a few limitations to their work. Because the study only began observing the children at age nine, the researchers likely missed the earliest and fastest phases of puberty for some of the participants. Additionally, the observational nature of the research means that the scientists cannot definitively prove that economic hardship causes early puberty, only that the two are linked.

The researchers note that the effect sizes found in the study are relatively small for any individual child. However, they provide evidence that is meaningful at a population level, given how many children grow up in financially disadvantaged environments.

Future research should aim to follow children starting at an even younger age to capture the complete timeline of physical maturation. The scientists also hope to explore the exact biological processes, such as stress hormone changes, that speed up physical development in humans.

“One goal is to better identify children who may be at increased risk for mental health problems by understanding how socioeconomic disadvantage shapes biological development,” Rakesh said. “In the longer term, this could help inform earlier identification and prevention efforts.”

The study, “Socioeconomic disadvantage, pubertal development, and adolescent mental health and academic achievement: A longitudinal study,” was authored by Kate Fitzsimons, Qingyang Li, Phoebe Thomson, Niamh MacSweeney, and Divyangana Rakesh.