PremiumHome / LifestylePuberty starts earlier than it used to. Nobody knows whyBy Azeen GhorayshiNew York Times·24 May, 2022 06:00 AM10 mins to readGift articleSubscriber benefitThe ability to gift paywall-free articles is a subscriber only benefit. See more offers by clicking the button below.Subscribe nowAlready a subscriber? Sign in hereSaveShareShare this articleReminder, this is a Premium article and requires a subscription to read.Copy LinkEmailFacebookTwitter/XLinkedInRedditStudies in dozens of countries show the age of puberty in girls has dropped by about three months per decade since the 1970s. A similar pattern has been seen in boys. Photo / Jyotirmoy Gupta, Unsplash