A teenager’s lifespan has been extended to between ten to 24 years old, from the previous 14 to 19, scientists say.
Factors such as longer time spent I education, delayed marriage and older parenthood has pushed back what has long been considered the start of adulthood, the BBC reports. Changing the definition of “teenager” or “adolescent” is important in order to make sure laws remain relevant and appropriate, experts say.
However, critics say that extending the age risks “further infantilizing young people.”
Puberty is considered to set in when the hypothalamus starts releasing a hormone that triggers a body’s pituitary and gonadal glands. Previously, the age of this onset was 14, but it has dropped to as young as 10 as a result of improved nutrition and health in many developed countries.
In most industrialized countries, the average age for a girl’s first menstruation has fallen by four years in the past 150 years – half of girls now get their period by 12 or 13 years old.
Other arguments for pushing back the years of adolescence are based on biological developments, such as the fact that the brain continues to mature past 20 years old and wisdom teeth come out until around 25 years old.
Currently, young adults are also getting married and having kids at a later age. In the United Kingdom, the average age for males to get married the first time was 32.5 years in 2013, and 30.6 years for women. This is almost an eight-year increase since 1973.
Susan Sawyer, director of the center for adolescent health at the Royal Children’s Hospital in Melbourne, lead author, says,
Although many adult legal privileges start at age 18 years, the adoption of adult roles and responsibilities generally occurs later.
She explains that these delays mean “semi-dependency” that is characteristic of adolescence. This shift needs to inform policymakers, Sawyer says. “Age definitions are always arbitrary…our current definition of adolescence is overly restricted. The ages of 10-24 years are a better fit with the development of adolescents nowadays.”
The opinion piece was published in the Lancet Child & Adolescent Health.