Monkeys will pay to look at images of sexually attractive or socially powerful primates. Male rhesus monkeys will give up a drink of cherry juice in order to look at a picture of a face of a socially dominant monkey, or of a female’s hindquarters. However, it seems that the monkeys have to be paid to look at a picture of a subordinate, as they only take a peek at the picture if they are bribed with a larger than normal drink.
Sylvia Shults, author 