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

A young exhibitor arrives with her kitten on a lead at the National Cat Club show at Crystal Palace, London. (Photo by Fox Photos/Getty Images). 2nd December 1931

Soldiers, including two recruits who have brought some chickens, at Victoria prepare to board the train for the battle front. (Photo by Hulton Archive/Getty Images)

Everyone wants to get something for nothing - whether it's a lucky upgrade that means you can turn left when you get on a plane instead or heading off into the economy seats, or even getting a few extra features thrown in for free when you buy a new car.

As some of the sharpest businesses around, no-one understands this quite as well as casinos and that's why they all have a system that they call comps. It's short for "complimentary offers" and these are special treats specially designed to reward you for your loyalty to the casino in question. They're basically bonuses.

Just a week before Rio de Janeiro hosts South America's first Olympics, city residents expressed mixed feelings about the cost and security of the Games, while holding out hope they will bring joy to a nation facing economic and political crises. The conflicted thoughts mirror a recent survey by the Datafolha polling group showing that half of Brazilians were opposed to holding the Games, while 63 percent think the costs of hosting the event will outweigh benefits. (Photo by Pilar Olivares/Reuters)

Indigenous dancers participate in a traditional healing ceremony for the mother earth at El Salvador del Mundo Square in San Salvador, December 10, 2014. Salvadorean indigenous organizations participated in a ceremony to ask for solutions to stop climate change and respect planet earth as the U.N. Climate Change Conference COP 20 is bring held in Peru. The two-week long United Nations climate summit opened on December 1 in Lima, with experts and analysts from around the world gathering to discuss melting glaciers and extreme weather patterns. (Photo by Jose Cabezas/Reuters)

Photographer Anna Radchenko explores this theme in her project “Reverse Side of a Mother’s Love,” where mother love becomes more than just mother-daughter relationship and causes some strange feelings. She visualizes, sadly, typical psychological problems in parent-child relationship: unrealized wishes of the parents, excessive strictness, total control and overprotection.

Jared Leto, holding a model of his own head, attends The Metropolitan Museum of Art's Costume Institute benefit gala celebrating the opening of the “Camp: Notes on Fashion” exhibition on Monday, May 6, 2019, in New York. (Photo by Charles Sykes/Invision/AP Photo)