Read letters from medical doctors and scientists in support of Resolution 35.

Is it really so farfetched to compare this situation with that of human prisoners kept in concentration camps?
-- Viktor Reinhardt. (Former UW-Madison primate veterinarian.) Reinhardt, V. 2001. Environmental Enrichment for Caged Macaques. Second edition. Animal Welfare Institute.

The point is, do rhesus monkeys have emotions? Do they have feelings? Do they have pain? Do they have sophisticated social structures? All the answers are yes.
-- Jane Goodall. April 20, 1993. "Animal Research Upsets Goodall" Capital Times

Nonhuman primates are capable of advanced behaviors that share important and fundamental parallels with humans. These parallels include highly developed cognitive abilities and binding social relationships. The behavioral repertoire of these animals makes them valuable models for research on the functional effects of exposure to neurotoxic agents.
-- Burbacher TM, Grant KS. 2000. Methods for studying nonhuman primates in neurobehavioral toxicology and teratology. Neurotoxicology and Teratology. Jul-Aug; 22(4): 475-86. Review.

Fagot, Wasserman and Young, writing about their work on abstract conceptualization in baboons: “To be sure, the stakes are high. What is at issue is no arcane point, but the very distinction between the minds of human beings and nonhuman animals.”
-- Fagot J, Wasserman EA, Young ME. 2001. Discriminating the relation between relations: the role of entropy in abstract conceptualization by baboons (Papio papio) and humans (Homo sapiens). Journal of Experimental Psychology and Animal Behavioral Processes. Oct; 27(4): 316-28.

The macaque infant differs from the human infant in that the monkey is more mature at birth and grows more rapidly; but the basic responses relating to affection, including nursing, contact, clinging, and even visual and auditory exploration, exhibit no fundamental differences in the two species. Even the development of perception, fear, frustration, and learning capability follows very similar sequences in rhesus monkeys and human children.
-- Harry Harlow. 1958. "The nature of love." Address of the President at the sixty-sixth Annual Convention of the American Psychological Association, Washington, D. C., August 31, 1958. First published in American Psychologist, 13, 573-685.

A majority of rhesus monkeys will consistently suffer hunger rather than secure food at the expense of electroshock to a conspecific.
-- Masserman JH, Wechkin S, Terris W. "Altruistic" behavior in rhesus monkeys. Am J Psychiatry. 1964 Dec;121:584-5.

Animals do a lot of things instinctively…. But people--and probably monkeys--have the ability to think 20 steps into the future: `In the end I'm going to feel great, because I worked hard to get there,' or `I'm going to get a lot of credit for this.' It's the prefrontal cortex that brings those emotions into play and guides us in our behavior. If we didn't have a sense of what would be wonderful or awful in the future, we would behave very haphazardly.
-- Ned Kalin (UW primate center) in "Wired For Sadness." Discover. April, 2000.

… it is not usually possible to study the activity of individual neurons in awake humans, so we perform our experiments with alert monkeys that have been trained to report what they are perceiving by pressing levers or by looking in a particular direction. Monkeys' brains are organized like those of humans, and they respond to [visual] stimuli much as humans do. Consequently, we think the animals are conscious in somewhat the same way as humans are.
-- Logothetis NK. "Vision: a window on consciousness." Scientific American. 1999 Nov;281(5):69-75. Updated in "The Hidden Mind." Scientific American. 2002 Aug; 1(12):18-25.

See also:

"How like us need they be?" Bogle, R. 2002

"Altruistic" Behavior in Rhesus Monkeys Masserman JH, Wechkin S, Terris W. "Altruistic" behavior in rhesus monkeys. Am J Psychiatry. 1964

A Natural History of Peace Robert M. Sapolsky. Foreign Affairs. January/February 2006.