A young arab boy, armed with a rifle and a knife, in the Aden Protectorate near Yemen. (Photo by Richards/Fox Photos/Getty Images). February 1938

The Lady Boys of Bangkok have fun at the Meadows August 1, 2006 in Edinburgh, Scotland. (Photo by Jeff J Mitchell/Getty Images)

A British policewoman chasing after a group of naked street boys by the Serpentine in Hyde Park, London. (Photo by Reg Speller/Getty Images). 1926

In this May 24, 2016 photo, a young boy descends the Qullqip'unqu mountain looking out at the tens of thousands of pilgrims gathered to celebrate the three-day festival Qoyllur Rit’i, translated from the Quechua language as Snow Star, in the Andean Sinakara Valley, in Peru's Cusco region. The celebration that mixes Catholic and indigenous beliefs honors Jesus as well as the area’s glacier, which is considered sacred among some indigenous people. While the native celebration is far older, the Christian part of the ritual stretches back to the 1700s, when Jesus is said to have appeared to a young shepherd in the form of another boy. (Photo by Rodrigo Abd/AP Photo)

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

An Afghan girl harvests Cotton buds at a field on the outskirts of Balkh province, Afghanistan, November 15, 2014. (Photo by Sayed Mustafa/EPA)

Girls ride on a donkey cart with grass for animals on the outside of Nangarhar province, Afghanistan May 19, 2015. (Photo by Reuters/Parwiz)

Girls sits on a bench during summer at the Central Park in New York, United States, 2011. (Photo by An Rong Xu)