Children who grow up without a father in the home during their first year of life may experience physical signs of puberty earlier than their peers. A recent study published in the Biology of Sex Differences suggests that the timing of a father’s absence is linked to the onset of specific developmental milestones in both girls and boys. These findings offer new insights into how early family environments might shape biological development over time.
The transition from childhood to adulthood is a complex biological and social process. Across various countries, data indicates that children are beginning puberty at younger ages than in previous generations. Entering puberty earlier than same-aged peers is associated with a greater risk for depression, risk-taking behaviors, and long-term health issues like heart disease.
Biological factors such as body mass index and genetics account for a large portion of this variation, but they do not completely explain why some individuals develop earlier than others. Social and family experiences also appear to play a role in physical maturation. Evolutionary models, such as Life History Theory, propose that early life stressors act as environmental cues. This theory suggests that unstable family environments might prompt the body to accelerate reproductive development as an adaptation to perceived adversity.
One prominent feature of the childhood environment is the presence or absence of a father in the home. Previous research has identified father absence as a reliable predictor of earlier puberty in girls. Much of this past research relied on retrospective self-reports of a single, late-stage pubertal milestone, such as a girl’s first menstrual period. Studies rarely tracked how a father’s presence fluctuated over a child’s life, and they often excluded boys entirely.
Taylor M. Drazan, a clinical science graduate student at Indiana University Bloomington, and Natasha Chaku, an assistant professor in the developmental area at Indiana University Bloomington, designed a study to address these gaps.
“Puberty is beginning earlier across cultures and generations,” Chaku said. “Father absence is one of the most consistent psychosocial predictors of earlier pubertal timing, but most previous research has treated father absence as a binary construct which does not fully capture the real experiences of families in the U.S.”
Chaku noted that the team wanted to explore the varying conditions of home life. “We were interested in whether the timing, stability, and consistency of father absence across childhood might matter for development,” Chaku said. “We also wanted to include boys, who have historically received much less attention in research on family environments and pubertal timing.”
The researchers analyzed data from the Future of Families and Child Wellbeing Study. This long-term project tracked 4,898 children, including 2,341 girls, from 20 cities across the United States. Mothers reported on the father’s presence in the household at the time of the child’s birth, and again when the child was one, three, five, and nine years old.
Based on these reports, the scientists identified four distinct patterns of father absence. About 38.9 percent of fathers were consistently present throughout the first nine years, and 39.3 percent were consistently absent. Another 15.6 percent were present early in the child’s life but absent later. Finally, 6.2 percent were absent early in the child’s life but returned to the household later in childhood.
To assess pubertal timing, the researchers looked at several distinct physical milestones at age nine. For girls, they tracked thelarche, which is the onset of breast development. For boys, they tracked the initiation of facial hair growth. In both sexes, they also measured the growth of pubic and underarm hair.
The scientists adjusted their statistical models to account for several outside variables. These included whether the child was raised by non-biological parents, how often the mother was present, and whether the mother lived with a new partner. They also accounted for the mother’s age at birth and the child’s race or ethnicity.
For girls, the analysis found a link between early father absence and breast development at age nine. Specifically, 66.2 percent of girls with consistently absent fathers had started breast development, compared to a base rate of 52.5 percent among girls with consistently present fathers. Girls whose fathers were absent early on but returned later showed a similar absolute rate of 66.5 percent. Girls whose fathers left later in childhood showed an absolute rate of 55.3 percent.
A similar pattern emerged for boys regarding facial hair growth. Among boys with consistently absent fathers, 4.1 percent exhibited facial hair growth at age nine, compared to just 0.1 percent of boys with consistently present fathers. Boys whose fathers were absent early but returned later showed an absolute rate of 5.2 percent. For boys whose fathers were present early but left later, the rate was 3.9 percent.
“One of the most interesting findings was how similar the results were for girls and boys,” Chaku told PsyPost. “Previous research has been much more consistent in girls, in part because puberty is harder to measure in boys, so finding associations with boys’ pubertal milestones suggested that boys may be more sensitive to family context than the existing literature would imply.”
“The main takeaway is that the timing of father absence seems to matter,” Chaku added. “Children whose fathers were consistently absent, as well as children whose fathers were absent early in life but later returned to the household, were more likely to show signs of pubertal development by age 9, highlighting the importance of early life father absence on child outcomes. Importantly, we saw similar patterns in girls and boys, suggesting that boys’ pubertal development may also be sensitive to early family environments.”
Despite these patterns in breast and facial hair development, the researchers found no statistically significant differences between the groups regarding pubic and underarm hair growth. The researchers noted that pubic and underarm hair growth is driven by a separate hormonal process in the adrenal glands. This process might respond differently to environmental factors than the hormones driving breast and facial hair development.
The study also asked children and parents to compare their physical development to their peers. At age nine, parents’ ratings of their children’s relative development showed no statistically significant differences based on father absence. By age 15, the self-reported data indicated some minor variations.
Girls whose fathers left the household later in life tended to report maturing earlier than girls whose fathers were absent early but returned. Boys whose fathers were absent early but returned tended to report maturing earlier than boys with consistently present fathers. The researchers interpreted these peer comparison results with caution, noting that social comparisons might become less reliable near the end of puberty.
Finally, the researchers tested whether material hardship, a father’s depressive symptoms, or a child’s body mass index at age five might explain the link between father absence and early puberty. None of these proposed variables statistically explained the connection. This suggests that other unmeasured elements of the family environment might be associated with the observed biological changes.
“We were also surprised that material hardship, fathers’ depression, and children’s BMI did not explain the associations between father absence and pubertal onset,” Chaku said. “These are all plausible pathways linking family environments to biological development, but none significantly mediated the relationship in our study, which tells us that we still have a lot to learn about the mechanisms involved in these associations.”
Observational studies of this nature cannot determine that father absence directly causes earlier puberty. Families experiencing father absence often face a variety of overlapping social and economic stressors, making it difficult to isolate specific biological triggers. Unmeasured factors such as genetic predispositions or the quality of the parent-child relationship may also influence a child’s physical development.
“At the same time, I would not interpret these findings to mean that father absence causes early puberty,” Chaku said. “The effects were relatively small, they were not observed for every measure of puberty, and family structure is associated with many other early life experiences that could explain these results.”
Chaku further noted the need to temper conclusions. “The associations were also small and differed depending on which pubertal milestone we examined,” Chaku said. “In addition, this was an observational study, so other factors—such as genetics, prenatal experiences, family stress, or other environmental influences—could contribute to both father absence and pubertal development. Thus, we shouldn’t make causal interpretations of these results.”
The data relied on a mother’s report of a father’s residence in the household. Living outside the home does not necessarily mean a father is entirely absent from a child’s life.
“Our measure captured whether the biological father lived in the household, not the quality of the father-child relationship or how involved a nonresident father remained in the child’s life,” Chaku said. “Fathers can live outside the household and still be a very positive and important presence in their child’s life.”
The study sample consisted largely of urban, socioeconomically disadvantaged families within the United States. These specific environmental pressures might differ from those found in rural areas, wealthier demographics, or countries with different social welfare systems.
To better understand these patterns, researchers plan to study neuroendocrine systems, which are the biological networks that allow the brain to communicate with the body’s hormones. “A major next step is understanding why and how early life experiences become biologically embedded,” Chaku said. “The first year of life is a particularly interesting period to explore because several important neuroendocrine systems are developing, including the systems involved in reproductive maturation and the stress response.”
“We also want to move beyond simple measures of father absence or presence to better characterize father-child contact, parenting quality, family conflict, and instability,” Chaku added. “Those factors may help explain why early family environments are associated with individual differences in pubertal onset.”
“This study is not intended to suggest that any one family structure determines how a child will grow and develop,” Chaku said. “Families are extraordinarily diverse and intricate; their living arrangements do not tell us about the quality of relationships within them, when they are most impactful, or how they change over time. Instead, our findings suggest that developmental science may benefit from paying more attention to the timing and changing nature of children’s early environments rather than treating them as static experiences.”
The study, “Timing matters: a prospective investigation of father absence and pubertal timing in girls and boys,” was authored by Taylor M. Drazan and Natasha Chaku.