Tags: ambiguity, depression, foragers, paleolithic, stress
One might think that lab rats lead relatively cushy lives compared to their wild brethren (and no I’m not comparing graduate students to fraternity brothers). They’re well fed, provided with warm homes, kept in reasonably germ-free environments, and need not worry that a hungry owl or hawk will swoop down upon them at any given moment. On the other hand, tomorrow morning a graduate student might implant electrodes in their brains, expose them to carcinogens or inject them with high doses of experimental drugs, in an attempt to determine the dosages that will kill half of them. Perhaps, if they’re lucky, they’ll merely be guillotined and dissected. Maybe they’ll be allowed to live in peace for a few more weeks.
I’m not saying that being a lab rat is a bad thing. In fact, lab rats have made undeniable contributions to a wide variety of critical advances in biomedical science. Ignoble creatures, leading noble lives. Perhaps it’s penance for the unfortunate role they played in spreading the Black Plague. Who knows? Me. I’d rather be wild.
In experiments designed to determine the effect of ambiguity on behavior, rats have been trained to expect food when a high tone sounds and a mild shock or a lesser reward, such as water, when a low tone sounds. Over time, the high tone is lowered and the low tone is raised, to the point that the meaning of the tones becomes extremely ambiguous, and in response, the rats become anxious, disinterested, and mildly depressed. In Evolution For Everyone, David Sloan Wilson recalls one such experiment that he attempted to replicate as a high school student:
“Somewhere I read about an experiment where rats were trained to expect food at the sound of a high tone and water at the sound of a low tone. Gradually, the high lone was lowered and the low tone raised until their meaning became ambiguous, which supposedly made the rats go crazy.”
Dr. Wilson leaves it to his readers imagination as to whether he actually completed the experiment. More ambiguity.
It’s obvious, at least to me, that daily encounters with ambiguity are a common contributor to the chronic stress that now plagues much of humanity. In Why Zebras Don’t Get Ulcers, Robert Sopalsky lays out a comprehensive case for chronic stress being a root cause of the diseases of civilization with wit and clarity. In this book, Dr. Sopalsky describes an experiment that aptly demonstrates that a change in circumstances isn’t necessary to give rise to a great deal of ambiguity. Instead, rather than changing circumstances creating an ambiguity that makes future events less predictable, a static set of circumstances create an insoluble dilemma for the rats. In the specific experiment described in the book the rats are presented with a situation in which a requirement for survival, food, can only be attained by ignoring an engrained survival instinct, the avoidance of bright light. Rats are placed in a cage where food is found only at the center of the cage under a bright light and the perimeter of the cage is dark. The rats instinctively settle down in the dark perimeter, but to satiate their hunger they must move into the brightly lit center of the cage. They just can’t. Their rat instincts tell them that entering the light is the equivalent of rat suicide, and rats just don’t do that. It’s very much a no win situation, and the rats soon become frantic. Rats maintained in this situation long enough eventually give up, lying listlessly in dark. Martin Seligman has coined the term “learned helplessness” to describe this type of behavior, and it is probably one of the key causes of depression in human beings.
Depression is extremely rare among nomadic foragers, although it is much less rare, even common, among ex-foragers who have taken up more sedentary modern lifestyles. Thus, Dr. Sopalsky includes it among the illnesses he describes as diseases of civilization.
The take home message: Clarity people. Under certain circumstances, passive-aggressive behavior is a very effective means of punishing a friend or family member precisely because clarity, in what is probably already a tense situation, is completely lacking; for those being punished, the ambiguity, and thus the stress, is inescapable and often intolerable. The mind games played by the passive-aggressive are extremely stressful, and stress kills.
Tags: Cultural Evolution
Humans aren’t the only species that murders its own. Lions have more to fear from other lions than from other types of animals, with the possible exception of human beings. Once a male lion has established itself as the new alpha-male in a pride, either by killing or by driving out the previous alpha male, it routinely kills all the pride’s cubs. Male wolves behave similarly. And male bears will kill cubs that are not their own so that a female bear will become sexually receptive once again. Lions also kill other lions in territorial disputes. Our closest relatives, the chimpanzees, kill each other at a startling rate, and live in social groups in which extremely aggressive displays, often leading to open conflict, are a daily occurrence.
Although we are less violent and murderous than chimps, human beings have unfortunately established a violent means of death that is unknown among other animals. Human beings self-destruct. And I’m not referring to the fact that many of us stay in bad relationships or do jobs that we hate. No, here I’m referring to the lamentable reality that every year a large number of human beings kill themselves. In fact, the person most likely to purposefully end your life is you. The World Health Organization now estimates that approximately one million people commit suicide each year; that’s more deaths than are caused by war and homicide combined. Moreover, this plague is becoming worse rather than getting better. In fact, the global increase in the rate of suicide over the past 60 years has been stunning. Moreover, the true number of suicides each year is likely much higher than has been reported: Suicide is a particularly shameful death in much of the world, and other causes of death are sometime listed on death certificates to spare the victims family unnecessary shame. In some societies, suicides are not even recorded, making it impossible to accurately determine the true global rate of suicide. Even so, in many countries, suicide is now ranked among the top ten causes of death.
Understanding the root causes of suicide has been the focus of a significant amount of exhaustive research. It may be that the primary causes of suicide differ from place to place. However, it is clear that lost status, precipitated by things such as unemployment or demotion, broken relationships, poor school performance and lost friendships, often plays a prominent role.
We are the only animal species of which individuals intentionally take their own lives. On rare occasions, cetaceans will beach themselves, however, this behavior is generally believed to be caused by a response to various infectious diseases. Certainly, nothing similar to suicide is observed among other primates. Chimpanzees don’t hang themselves, throw themselves into rock outcroppings headfirst from high tree branches, nor doe they sacrifice themselves to dangerous predators, or otherwise destroy themselves. Suicide is essentially a human behavior. And it has now reached epidemic proportions.
What this means is uncertain. However, our current lifestyle is unprecedented. Our diets, the excessive time we spend indoors, our lack of physical activity, our artificial hierarchies: all of these things probably contribute to the chronic stress many humans, perhaps most, experience on a near daily basis, and chronic stress is one of the primary causes of many human diseases, including several mental health disorders, such as chronic major depression. Our bodies, and therefore our minds, did not evolve to thrive in modern societies whose only constants appear to be rapid and continual change. We congratulate ourselves on having, in large part, overcome the elements, on having become civilized. Perhaps we should not. Something about the way we live has given rise to an all too prevalent feeling that life has become an unbearable burden, full of despair and lacking meaning.
What can be done?
Tags: supplements, vitamin D
One all too common consequence of the sedentary, sheltered lives we typically lead these days is Vitamin D deficiency. Vitamin D isn’t really a vitamin at all, but a hormone produced by the body when its exposed to sunlight. Unfortunately, many of us don’t spend much time outdoors these days. Not only are we usually sequestered away in our homes, schools or offices most of the time, some of us, for fear of being struck by a very deadly form of skin cancer known as melanoma, are limiting our exposure to an even greater extent now by liberally applying sunblock before venturing into the great outdoors for any great length of time. Although this hasn’t resulted in a new pandemic of Ricketts, it’s become apparent that low levels of Vitamin D can make us vulnerable to a wide variety of other types of health problems, including osteoporosis, muscle weakness, prostate and breast cancer, autoimmune disease, diabetes, schizophrenia, depression, and cardiovascular disease. In fact, nearly everyday a new clinical study is published showing that Vitamin D ameliorative effects on one disease or another, or showing that low levels of Vitamin D correlate with this or that unhealthy condition. That’s why a recent perspective in JAMA suggests that the minimum recommended daily intake of Vitamin D be revised upwards. Of course, people might also consider spending a little more time outdoors. A little sun can be good for you. And a bit of fresh air wouldn’t hurt either.