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

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

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

A traditional game that earned hollers from the crowd saw a male rider gallop after a young woman, stretching for a kiss. Only a handful of the men managed the risky peck before the young women turned the tables and thundered after the men with whips in hand. (Photo by Amos Chapple/Radio Free Europe/Radio Liberty)