Ben Cosgrove examined an invention that, 70 years later, remains controversial:

• Up until the second world war you were either a child or an adult.
• Then in 1944 Life published an article titled “Teen-Age Girls: They Live in a Wonderful World of Their Own”.
• It spoke about a special time in an individual’s life preoccupied by fashion, parties, and boys – before they were sent off to war.
• The article noted that teens were a lucrative and unique market for businesses to target.
• It was a success. “Teen-agers” soon turned into teenagers and became firmly rooted in the general conscience as a distinct group of people.

Read more on Time.

Via: Cracked