Ethics in Animal Research
There is little doubt that we can learn a lot about human behavior through the study of nonhuman primates. These animals are the closest taxonomical relatives to humans and are not only similar in skeletal structure but in behavior as well. Many behaviors commonly observed in the social interactions of humans are also portrayed in the social interactions of monkeys and other primates. It is for this reason that so many experiments are done on nonhuman primates when it is deemed inappropriate to use human subjects. Between 1959 and 1973, Harlow and his colleagues performed a series of experiments in which they studied primates in various situations. Findings from these studies were key points in furthering developmental theory.
In Harlow (1959), experimenters took eight baby rhesus macaques away from their mothers just a few hours after birth and placed them with substitute “mothers” in order to test Freud’s drive-reduction theory of emotional attachment between mother and child. Babies were placed with two substitute mothers in a cage, one made of wire and the other of terry cloth. Four monkeys were fed by the wire mother, and four by the terry cloth mother. Experimenters found that regardless of who fed them, all the monkeys much preferred the terry cloth mother. These findings showed the importance of body contact and the comfort it offers infants, and suggested that infants form attachment to mothers based not on the biological drive to eat, as Freud had suggested, but on the soothing comfort of physical contact.
Subsequent experiments by Harlow and colleagues helped support these new findings. A year after separation from the substitute mothers, the young monkeys raised with a wire mother that fed and a terry mother that had no food still showed preference to the cloth mothers when given three levers that would allow them to see either the cloth mother, the wire mother or an empty box. They showed no more interest in the wire mother than the empty box (Harlow & Zimmerman, 1959). In strange or fearful situations, baby monkeys ran to the cloth mothers and not the wire mothers for comfort (Harlow & Harlow, 1969). These experiments showed a clear link between attachment and physical comfort.
While Harlow’s studies revealed much insight about human psychological development, there are still ethical issues regarding the use of primates...