The idea came about from studies of young children.
Studies of young people who become too old for foster care underscore the risks faced by a population often scarred by abuse and neglect.
Ethnographic studies of young girls in LA or male university students, meanwhile, show the girls acting confrontationally and the boys gossiping.
Eric Rohmer, who will be 78 in March, has confected the best baguettes of all: a score of luminous, affectionate, often poignant studies of young or adolescent romance.
And some of the canvases of the classical period in the 1920s, especially two monumental studies of young men together, bring an unexpectedly watchful eye to ancient ideas of masculine friendship.
For example, she points out that studies of young children have shown that boys are no more likely than girls to enjoy playing with a toy with wheels, something traditionally given to boys.
They point out that long-term studies of young children with gender dysphoria have found that only about fifteen per cent continue to have this feeling as adolescents and adults.
This celebrated fashion and figure photographer, whose studies of young men romping naked in the wilderness with big, happy dogs established a new category of all-American homoeroticism, has here created an eccentric, highly personal guided tour of some of his favorite people, places and things.
For the cost of an entry-level Birkin, the new issue includes work by the artists Anselm Kiefer and Lucian Freud, the photographer Adam Fuss and a tribute to Ann Demeulemeester men's wear (above) — shot, by Mr. Heck, in the style of the Italian photographer Mario Giacomelli's studies of young priests.
The exhibition also includes work not normally associated with the nature-and-natives reputation of the early National Geographic, like the obsessive, homoerotic pictures of Baron Wilhelm von Gloeden, a German photographer known for his idyllic nude studies of young Sicilian boys.
Mr. Ethridge's clever orchestration of his own almost hallucinogenically clear photographs includes portraits of UPS delivery men in their trucks, head shots of two pretty young female models, close-up studies of young pine trees and a big picture of an ambulance that had just crashed.
