Young female Ibex on the fork of Disteis (2,200 m), near the top of the Jof di Montasio (Friuli, Italy). (Photo by Stefano Zocca)

Young man making the O.K. sign. (Photo by George Marks/Retrofile/Getty Images). Circa 1950s

Three young women preparing a guy. They are sitting him on a keg labelled “gun powder”. (Photo by Fox Photos/Getty Images). 1929

Father Christmas reading with three young children. (Photo by Spencer Arnold/Getty Images). Circa 1915

Young U.S. visitors pose for a photograph next to a vintage car in Havana March 16, 2016. (Photo by Ueslei Marcelino/Reuters)

Juno, a Beluga whale, greets a young viewer at the Mystic aquarium in Connecticut, USA on December 5, 2015. (Photo by Tim Clayton/Corbis)

“The girl behind the camera and the girl in front of the camera”, May 2012. (Photo by: Mandy Rosen; Source: Flickr)