How do you feel about the use of animals as research subjects in psychological studies? Back up your position with evidence.

Pro: Relatively few psychological studies involve animals, and of those that do, few expose animals to harm or pain; researchers can more precisely control the environment of animal subjects; animal research has generated important advances in the treatment of mental and physical disorders in humans; the knowledge gained justifies the risks.
Con: Animals should have the same rights as human subjects; research animals are sometimes treated inhumanely; many psychological studies using animals are trivial; the results of animal studies may not generalise to humans.