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)

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

A young man “painting” the Eiffel Tower. (Photo by Keystone/Getty Images). 9th May 1970

In this Sunday, March 29, 2015 photo, a young performer from the Parinacochas district of Ayacuhco dances in the Vencedores de Ayacucho dance festival, in the Acho bullring in Lima, Peru. The performers sang in the Quechua language, portraying the planting of corn and potatoes. From very young children to elderly people dressed as farmers, tigers, and foxes, as well as members of auto-defense groups, soldiers and police officers, to portray the violence that tore apart their families and communities. (Photo by Rodrigo Abd/AP Photo)

Young Palestinians form an obstacle to be jumped over during a military-style exercise graduation ceremony organised by the Hamas movement, in Gaza City August 5, 2015. Thousands of young Palestinians joined Hamas military-style summer camps during school vacation in the Gaza Strip to prepare them to “confront any possible Israeli attack”, organisers said. (Photo by Suhaib Salem/Reuters)