From his early years growing up on the farm, and continuing into his time as a Ph. D. student, Barnes accepted the idea that non-human animals exist to serve human purposes. As a student of psychology, he was also taught a whole new vocabulary which served to distance the experimenter from the animal. The monkeys on which he worked became 'research subjects'; the electric shocks he gave them were called 'negative reinforcement' and their vain efforts to escape were classified as 'avoidance behaviour'. As Barnes says: 'During my sixteen years in the laboratory the morality and ethics of using laboratory animals were never broached in either formal or informal meetings prior to my raising the issues during the waning days of my tenure as a vivisector'.

Don Barnes is not the only one to have escaped his conditioning. In 1977 the magazine Monitor, published by the American Psychological Association, reported that experiments on aggression carries out by Roger Ulrich had been singled out before a Congressional subcommittee as an example of inhuman research. In a response that must have surprised the Editor of Monitor, Ulrich wrote back to say that he was 'heartened' by the criticism of his research; and he added:

Initially my research was prompted by the desire to understand and help solve the problem of human aggression, but I later discovered that the results of my work did not seem to justify its continuance. Instead I began to wonder if perhaps financial rewards, professional prestige, the opportunity to travel, etc. were the maintaining factors, and if we of the scientific community (supported by our bureaucratic and legislative system) were actually a part of the problem...

When I finished my dissertation on pain-produced aggression, my Mennonite mother asked me what it was about. When I told her she replied, 'Well, we knew that. Dad always warned us to stay away from animals in pain because they are more likely to attack'. Today I look back with love to monkeys who submitted to years of torture so that like my mother I can say, 'Well, we know that...'