non-human primates are studied for several reasons. They are studied simply to improve our understanding of the world and all that is in it. they are also studied to help up better understand where we (humans) may have come from and thus why we do much of what we do and what our motivations are.
FYI-answering a question such as this is very difficult to do as you are asking essentially for the motivation of all researchers, and I assure you that each of them has a different set of questions and motivations that drive their research.
Primatology is the scientific study of primates, which includes monkeys, apes, and prosimians. Primatologists study primate behavior, biology, evolution, and ecology to better understand the complexities of our closest living relatives in the animal kingdom.
They aren't all non-human because humans are primates. Other primates include monkeys and chimpanzees and orangutans and gorillas, which are non-humans because they're not human.
Most of them do.
The primate fossil record and genetic relatedness between human and modern non-human primates.
Besides humans, some look at primates that are closer to human DNA.
Primatology.
Non-human primates are classified into two main groups: Prosimians (lemurs, lorises, and tarsiers) and Anthropoids (Old World monkeys, New World monkeys, and apes). Humans are classified as part of the family Hominidae, along with great apes like chimpanzees, gorillas, and orangutans.
Primates
Counting out the human being....most likely Primates
Primates are characterised by large brains relative to other mammals. Their eyes face forward, giving them stereoscopic vision and vision is the sense they rely on most rather than smell like other mammals. Most primates with a few exceptions have opposable thumbs and have developed adaptations to climb trees. Primate babies take a long time to mature because of their brain size, relative to non-primates. Non-human primates have oestrus cycles and many species display swellings during their fertile period.
oragatangas
They probably study ancient primates, like gigantopithecus.