Growing Up Earlier: What’s Going On With Puberty?
What the latest research says about puberty’s shift and its impact on kids’ mental health.
It’s a question that has been making headlines for years: are kids today hitting puberty earlier than previous generations? Some research says yes, while others are still debating the factors at play. Let's dive into the research and the impact it may have on our kids' mental health and wellbeing.
Key Definitions: What Do We Mean by "Puberty"?
Puberty is the stage in development when kids’ bodies begin to change, becoming capable of sexual reproduction.
This includes physical changes like breast development in girls and increased muscle mass in boys.
Puberty also triggers shifts in emotional and psychological development, as kids experience hormone-driven changes.
Traditionally, puberty for girls begins around age 10-12 and for boys around age 11-13.
Research Spotlight: Is Puberty Really Starting Earlier?
Recently, more research suggests puberty is starting earlier. In 1860, the average age of the onset of puberty in girls was 16.6 years. In 1920, it was 14.6; in 1950, 13.1; 1980, 12.5; and in 2010, it had dropped to 10.5. Similar sets of figures have been reported for boys, but with a delay of around a year.
Here’s what research from 2012 to 2022 tells us:
2012 Study (Sun et al.): Found that girls as young as 8 are starting puberty, especially in urban areas.
2017 Review (Biro et al.): Highlighted a significant trend of earlier puberty in girls, particularly in Western countries.
2022 Studies (Tang et al. and Lu et al.): Found that modern factors like nutrition and exposure to environmental chemicals might be accelerating the process.
While the trend is real, it's complex, with multiple contributing factors.
Why Does It Matter? The Mental Health Impact
Earlier puberty doesn’t just affect kids physically—it has a real impact on their mental health:
2009 Study (Downing & Bellis): Found that early puberty is associated with teen drug use, earlier sexual debut (<14 years old), and alcohol use.
2010 Study (Copeland et al.): Showed that early-maturing girls tend to experience more emotional difficulties and engage in risky behaviors earlier than their peers.
2011 Study (Negriff & Susman): Found that early puberty in girls is linked to higher rates of anxiety and depression.
2015 Meta-analysis (Dimler & Natsuaki - that’s me!): Found that earlier puberty increases the risk for externalizing behaviors (think: aggression, delinquency).
Externalizing behavior trajectories by age, sex, and pubertal timing. Dimler & Natsuaki (2021) 2021 Longitudinal Study (Deardorff et al.): Confirmed that early puberty increases the risk of depressive and anxiety symptoms in girls across ethnicities.
Early puberty can make kids feel out of sync with their peers, which affects their emotional well-being. This can lead to struggles with self-esteem, peer relationships, and academic performance.
Why Is Puberty Starting Earlier?
There is no single cause, but several factors are believed to be behind this trend (note that these are all correlational, not causal):
Screen-Time: While screen time itself isn’t directly linked to early puberty, increased screen use is often associated with lower physical activity and higher rates of sedentary behavior. This can contribute to elevated body weight, which is a well-documented predictor of earlier pubertal onset — especially in girls (studies here and here).
Nutrition & Obesity: Higher-calorie diets and rising childhood obesity rates are associated with earlier physical development, especially in girls. While correlation doesn’t mean causation, excess body fat can influence hormonal activity, potentially contributing to earlier onset (studies here, here, and here).
Endocrine Disruptors: Some studies suggest that chemicals in plastics, pesticides, and personal care products—known as endocrine-disrupting chemicals (EDCs)—may influence hormone regulation, though more research is needed to confirm long-term effects in humans (studies here, here, here, and here).
Long Story Short: What Should We Take Away?
Yes, puberty is starting earlier, and this shift is impacting our kids' mental health. The exact reasons are still being studied, but early puberty is associated with an increased vulnerability to emotional challenges, including depression, anxiety, and risk-taking behavior - especially when kids lack support or feel socially isolated.
Quick Takeaways:
Puberty is starting earlier, especially for girls, and research supports this trend.
Mental health challenges like anxiety, depression, and self-esteem issues are more common among early-maturing kids.
Environmental factors (e.g., diet, chemical exposure, and screen habits) are associated with earlier puberty, though the exact mechanisms are still being studied.
Parents should be proactive about supporting kids through these changes, including fostering open communication and providing mental health resources.
What Can Parents Do?
If your child is going through puberty earlier than expected, here are a few things to keep in mind:
Open Communication: Talk about body changes and feelings. Normalize what they’re experiencing. Use age-appropriate language and don’t just have ‘the talk’. Have multiple little talks from when they’re little.
Body Positivity: Encourage healthy body image and self-esteem. Don’t criticize yourself in front of your kids - they pick up on this and learn to do the same thing.
Mental Health Check-Ins: Be aware of emotional struggles like anxiety and depression, and seek help if needed.
Final Thoughts:
Puberty is a challenging time for kids, and when it happens earlier than expected, it can bring unique hurdles. Understanding the signs and knowing how to help your child navigate these changes can make a world of difference for their emotional health.
Super informative! I love that you show there’s a change and show that there MAY be some potential causes but we aren’t sure about them yet (rather than making a false claim) 😊
Another homerun, my friend. This is SO helpful in the counseling room.
Literally had an 18 yr old female client book with me today. I’ll be meeting her next week. It’s quite possible this very post comes up in session.
While I realize our society has politicized gender dysphoria (GD), I don’t see this as a political issue but rather a change in physiology.
What you’ve pointed out further demonstrates the increase in confusion as to what is happening to their bodies. Research shows that by age 19, the confusion subsides.
This leads me to believe that particularly in cases of early puberty, because it can bring such confusion and mental health problems, it is more important that we guide them through this phase in their lives rather than urge them towards permanent, life-altering physical changes. It just makes more sense.