I was revisiting Seligman and Maier's famous/notorious 1967 experiment on learned helplessness this morning, and what struck me was how similar the symptoms of the 'yoked' dog were to human depression.
In brief, the experiment (which is potentially quite upsetting to dog/animal lovers) involved two dogs - the control dog and the yoked dog. In the first part of the test, both dogs were administered mild electric shocks (harmless though annoying) at random times. However, the control dog's room had a beeper that sounded before the shock came and a switch that allowed the dog to turn off the electric shock. On the other hand, the yoked dog did not have the beeper warning nor the switch. The control dog soon learned to use the switch to prevent the shocks from occurring, while the yoked dog could do nothing about the shocks.
After the first round of experimentation, the dogs were transferred to a shuttle box.
What happens is that the electric shocks now come from the ground on either side of the shuttle box (halved by a fence). Like in the first experiment, electric shocks came at random times, but this time both dogs could witness a warning light coming on which signified the onset of another shock.
Having acclimated to the environment of the first experiment, both dogs transferred their knowledge into the second study. It was found that the control dog soon learned to jump over the fence whenever the light came on. Although it was understandably anxious, it appeared relatively happy.
The fascinating and depressing case was of the yoked dog - it simply lay in the corner of its shuttle box whimpering. Although it now had the means to escape the shocks like the control dog, the experience from the first experiment taught it that it did not understand the relationships between cause and effect. Consequently, the yoked dog became helpless in its general approach to life.
Even more interestingly/troublingly, the dog later exhibited symptoms similar to people suffering from chronic depression, such as ulcers and a weakening of the immune system.
I'm revisiting this study also at a time when I've recently watched The Cove, a documentary about dolphin captivity and a man's effort to fight against the dolphin industry after he witnessed Flipper's depression and suicide, and after I went to the zoo on Boxing Day. Did Flipper experience the same learned helplessness? Are animals in zoo captivity experiencing the same problems? I'm not entirely sure, because it doesn't appear like the zoo is making a blatant attempt at mistreating the animals, but at the same time we do not really know exactly what these animals are feeling.
In addition, it makes me wonder how the roots of depression form in human development. Even very mild cases of depression, such as low self-esteem which we certainly won't classify as depression, have symptoms that are associated with pessimism, helplessness, failure to perceive alternatives/options, etc.
I'm pretty sure that at some point some degree of learning happens in a child's life which tells him that he is either more empowered or more helpless (understanding vs not understanding the relationships between cause and effect). I think that the natural curiosity of children helps them figure this out at a very young age, and I've always believed that parents have an important responsibility to satisfy that curiosity. Other seemingly mundane aspects of a toddler's life, such as being able to turn on or off the room light switches, can also go a long way if caregivers of the toddler empower it to take matters into its own little hands.
Also, what aspects of depression are biological? Why is it that females experience this more than males - is it because women are less empowered, or could it also be in the biological makeup of the sexes? How does the body break down with the onset of depression? It appears that when a person (or any living social creature) experiences learned helplessness, the body also takes on a character of futility, indicating that our bodies work in tandem with our mental health (consider placebo effects, or how we get better when we actually believe we will get better).
Perhaps it all really stems from the basis of a social being's understanding of cause and effect, because with this understanding, it can take control of its life. This is the nature of empowerment.