Dogs and cats have evolved for thousands of years to be a domestic pet to man. Monkeys are wild. They will never adapt to being in a home. It is very expensive to keep a primate happy and healthy. A monkey that doesn't bite is extremely rare and their teeth are sharp.
Monkeys are impulsive, unpredictable and excitable.
The monkey can never be toilet trained. Monkeys should not be kept singly. They are social animals and socializing with you is not enough. They will become lonely and become sick or die. While this is a review about monkeys in general, when specifications are mentioned, the size of monkey that is being referred to is the size of a Capuchin, Squirrel or Spider Monkey.