Scientists Still Can't Explain The Mystery Behind Gen Alpha's Growing 'Epidemic'

Generation Alpha is experiencing higher rates of "precocious puberty" — beginning puberty at an earlier age than normal — than previous generations. Increasing numbers of girls as young as six are developing breasts, and the trend is especially pronounced in African American girls. This rising rate has been observed since the '70s, and a 2020 study found that the age of puberty's onset among girls has fallen by an average of three months per decade. As a result, Gen Alpha is the generation with the earliest start to puberty.

But if scientists have been monitoring this downward trend for so many decades, why hasn't the cause been discovered? After all, Gen Z's deadly "loneliness epidemic" has been linked to more time spent online and less time spent socializing in person, even though scientists only observed the trend within the last few years. Unfortunately, the cause is likely due to a number of compounding factors that aren't easily identified, similar to how scientists are also scrambling to discover why colorectal cancer rates are on the rise among young adults.

There are only two known risk factors for precocious puberty: sex and obesity. Females have around two to twenty times the risk of developing precocious puberty than males. Scientists thus believe that increased childhood obesity is the main driver behind the early-puberty epidemic, especially since the mechanism behind it is so well-understood. Excess fat mimics the endocrine organ and tells the brain that the child has adequate energy stores to support a pregnancy, even before the rest of their body is prepared. Nonetheless, experts believe that other, yet-unconfirmed factors may be driving Gen Alpha's early-puberty epidemic, as well. 

Obesity is known to drive the onset of puberty, especially in girls. In fact, the mechanism behind how fat triggers puberty is well-established. Essentially, fat tissue produces hormones, including leptin and estrogen. The more fat, the more hormones. This abundance of hormones signals the brain that the body is ready for reproductive development. Evolutionarily, this makes sense, since high fat reserves are required to support a pregnancy during periods of food insecurity. But today, children often gain these fat reserves years before our ancestors did due to sugary, fatty diets.

Obesity may be the main driver of precocious puberty, but it's not the only one. Doctors noted that cases spiked after the 2020 COVID-19 pandemic, even among groups where obesity rates didn't rise. At the time, Gen Alpha was between the ages of 0 and 10, a critical stage in their development. Quarantining drove Gen Alpha to spend more time isolated in front of computers, which may have affected their bodies' endocrine systems, sleep cycles, social skills, and mental health. Recent studies show that the cognitive development of Gen Alpha has been powerfully influenced by their excessive screentime, so it's a safe bet that it affected their physical development, as well.

Some researchers believe increased exposure to hormone-affecting chemicals is to blame. For example, phthalates are chemicals used in plastic manufacturing, including food containers, and they're abundant in trendy skincare products targeted towards Gen Alpha. Phthalates can act as endocrine disrupters, which change the behavior of hormones in the body. This theory has yet to be confirmed, but it may contribute to Gen Alpha's early-onset puberty "epidemic" — as if they didn't already have enough to deal with.