With a meter and a half in length, the muriquis recall the African great apes, andsome people call them Brazil’s gorillas. The size is impressive, but the major peculiarities are social relations of these monkeys, as found Dr Karen Strier, over more than twenty years of research. What most surprised the researcher was the total absence of aggression and dominance between individuals of a same group, common traits almost all the other apes, such as chimpanzees, social gorillas and orangutans. Between the muriquis, male and female adults have the same size and respect each other. They rarely fight or show aggressive behavior. In addition, the demonstrations of affection between individuals of any age or sex are everyday activities.