To watch a news broadcast you would think we lived at the most dangerous time in history. Every day we bombard ourselves with stories of terrorists, child abductions, natural disasters, tragic accidents, wars, new killer diseases and a host of dangers that are going to maim and kill us. However, in reality humans, particularly those of us living in developed countries, have never been so safe. Never in the history of mankind has the probability been so high that a baby born will reach adulthood and that an adult will live well into old age. This sets up an interesting dynamic-living in a time when we have fewer legitimate threats to our safety while being more aware than any time in history of threats to our safety.
For most of our evolutionary history our ancestors didn't understand many of the things that were likely to kill them. Certainly the things that had sharp teeth chasing after them or angry faced hominids that were chucking rocks at them were understood well enough. (This latter scenario probably happened more often than we can really appreciate. Steven Pinker did an interesting presentation on TED describing how human beings have less chance of being killed by another human being today than in any time in history-even if you count both World Wars.) Our fear response evolved to deal with these types of immediate threats that were generally dealt with quite quickly. Either the saber tooth tiger caught you or you got away, the human trying to steal your food and wife quickly clubbed you to death or you clubbed him first, and so on and so forth. Our ancestors evolved responses to react to such threats but also learned about such threats from anecdotes past on by friends and family.
The reliance on anecdotes is important to understanding our instinctual fears. Our ancestors relied heavily on stories to understand threats. Primarily these threats were other humans or animals but there was also the threat of poisonous food, floods, or other natural disasters that they taught each other about through stories. This is important to realize because we see that humans that instinctively enjoyed stories about dangers were more likely to survive than those who didn't. Consequently we see why news stories about terrorists attract a lot more attention than a local service project.
The reliance on anecdotes also explains why people like me are terrified of flying. No matter how many times I read the probability of my plane crashing being one in a million when I step on the plane my body shakes and sweats like my chance of survival is 50/50, if not worse. We didn't evolve around statistics-we evolved around stories. It's quite likely that our experience with people arriving safely from a flight-particularly if you were like me and had parents and acquaintances who rarely traveled-is fairly close to the number of times you've heard about disasterous plane crashes on the news. Consequently if you take the number of stories you have about plane crashes and line them up to the number of flights you've experienced or heard about from immediate friends and family it's quite likely your perceived risk from anecdotes could be closer to 50/50.
One thing our ancestors didn't understand at all was disease. We did evolve many instincts that protect us from disease-such as adverse reactions to bodily fluids or corpses-but we rarely had the understanding to communicate the danger of disease to each other and never fully understood how to appropriately respond. Disease is also ill-fitted for our evolved fear instinct because unlike the threats that haunted our ancestors that were quickly dealt with and went away disease is an ever-present danger. This is particularly true now that we understand so many diseases that don't require being next to a person with a sneeze, cough or oozing wound but that occur naturally within our own bodies like cancer or auto-immune diseases.
The last danger I'll mention that our ancestors didn't have to deal with is a particularly unique one. The danger of hell. Now, my point here is not to discuss whether hell is real or not. In fact I think the fear of hell can be joined with a danger that no one disputes as being real-social consequences for our actions. While humans have always interacted with each other and had to carefully weigh the consequences of their actions socially never has this equation in our lives been so complex and pitted so many of our instincts against one another. This includes the very complex social practices and beliefs we have incorporated to deal with our complex social interactions, such as religion, which throw in more dilemmas into the equation. It isn't that these social practices and restrictions aren't useful or at times even necessary-they generally are-but they add another layer of fear into a world that is already piling it on.
The result is we live in an environment that is perpetually bombarding our fear instincts. These instincts that were so helpful to our survival have consequently become a hinderance to many. Anxiety disorders have become almost pandemic in the developed world. Similarly depression, which is often preceded by anxiety and may simply be the anxiety instinct driven to exhaustion, has become a huge problem in our modern society. In my own state of Utah, for example, anti-depressant use is the highest in the nation. While research will continue to evaluate this problem it appears that a large part of our problem may be the evolution of fear in circumstance where 'fight or flight' was generally an available option placed in our current environment where our awareness of danger is too high and our ability to react is overwhelmed.
Friday, February 18, 2011
Friday, February 11, 2011
I Didn't Evolve Under These Circumstances. Part 1: Food
It's struck me a lot recently how many problems we have because progress has outpaced our evolution. I've decided to write a few posts about these problems and hopefully do a final one about some of the possible solutions.
Perhaps the most classic example of this is found in the way we eat and use our food for energy. Human beings as far as we can tell were hunter gatherers for the vast majority of our evolutionary history. We ran, a lot, and a lot of that running was spent getting food. And since food was relatively scarce we also became very efficient at using the calories we consumed. In fact, anthropologists suspect one reason we may have evolved to stand upright is because it burns fewer calories than walking on all fours like other primates. We even evolved instincts to conserve our calories. If we weren't running to catch prey (or to avoid becoming prey) or a few other evolutionary essential functions we instinctively moved around as little as possible.
About 10,000 years ago humans began cultivating crops. While this may have created conflict with our evolved instincts almost immediately initially raising crops was labor intensive and crop yields relatively low. There is some evidence that humans did evolve some with this change-since people with ancestory coming from geographic regions with a longer history of agriculture tend to have less obesity problems than those who didn't-but the change was relatively modest. Regardless of one's ancestoral evolutionary heritage the leaps and bounds in agriculture that have led to explosive gains in food output have left almost all of us ill-fitted instinctively to stay healthy. Our insticts, evolved over eons of time with food scarcity-have led us to eat much more than we need for health and to be as sedentary as possible. On top of that we evolved cravings for foods that were relatively scarce or difficult to attain but that are essential in small quantities that are now readily accesible such that we overconsume them-like fat and salt.
It's interesting the remedies we've tried to come up with to solve this problem. One novel idea is exercise. In the movie Back To The Future III the character Doc Brown in a saddened stupor begins rambling about the future to a packed bar in the late 1800's. He tells them that in the future people will run for recreation. A man in the bar immediately pipes up with "Run for fun? What the hell kind of fun is that?" with the fellow townspeople laughing in agreement.
Indeed the idea of exercising for recreation or enjoyment is rather ridiculous through the lens of most people throughout human history. Exercise wasn't something they fit into their lives-it was something they did to stay alive. Consequently we aren't very good at motivating ourselves to do it as we were when not running meant starving to death or being eaten by a sabertooth tiger. We struggle to get ourselves moving because the urgency simply isn't there.
Likewise we are not very good rejecting food,particularly delicious foods that we crave. Again, having too much food was a problem that few if any of our ancient ancestors would have faced on a regular basis-while starvation was a constant possibility. In the rare event that a smorgasbord was made available to our ancestors the extra fat reserves kept by the body would almost certainly have been burned off in a time when food became relatively scarce.
As bad as we are at exercise our capacity to deprive ourselves of food is even more dismal. It seems over the course of time our bodies did evolve some neurological rewards for running. When we run endorphins are released giving us an improved sense of well-being. But with food depravation just the opposite occurs. While depriving ourself of food does have benefits to the function of many of our organs, neurologically we are punished for it. Cortisol, a stress hormone, is released when we fast or reduce our caloric intake. This made sense for our ancestors-since it probably motivated them to look for food immediately since the time from when they started looking for food and when they actually found it would have often been quite long. However for modern humans this creates havock-reducing calories leads to stress that often leads to increased food consumption which then relieves the stress but leaves us overweight.
So our evolutionary past has clearly put us at a disadvantage in the battle of the bulge.
Perhaps the most classic example of this is found in the way we eat and use our food for energy. Human beings as far as we can tell were hunter gatherers for the vast majority of our evolutionary history. We ran, a lot, and a lot of that running was spent getting food. And since food was relatively scarce we also became very efficient at using the calories we consumed. In fact, anthropologists suspect one reason we may have evolved to stand upright is because it burns fewer calories than walking on all fours like other primates. We even evolved instincts to conserve our calories. If we weren't running to catch prey (or to avoid becoming prey) or a few other evolutionary essential functions we instinctively moved around as little as possible.
About 10,000 years ago humans began cultivating crops. While this may have created conflict with our evolved instincts almost immediately initially raising crops was labor intensive and crop yields relatively low. There is some evidence that humans did evolve some with this change-since people with ancestory coming from geographic regions with a longer history of agriculture tend to have less obesity problems than those who didn't-but the change was relatively modest. Regardless of one's ancestoral evolutionary heritage the leaps and bounds in agriculture that have led to explosive gains in food output have left almost all of us ill-fitted instinctively to stay healthy. Our insticts, evolved over eons of time with food scarcity-have led us to eat much more than we need for health and to be as sedentary as possible. On top of that we evolved cravings for foods that were relatively scarce or difficult to attain but that are essential in small quantities that are now readily accesible such that we overconsume them-like fat and salt.
It's interesting the remedies we've tried to come up with to solve this problem. One novel idea is exercise. In the movie Back To The Future III the character Doc Brown in a saddened stupor begins rambling about the future to a packed bar in the late 1800's. He tells them that in the future people will run for recreation. A man in the bar immediately pipes up with "Run for fun? What the hell kind of fun is that?" with the fellow townspeople laughing in agreement.
Indeed the idea of exercising for recreation or enjoyment is rather ridiculous through the lens of most people throughout human history. Exercise wasn't something they fit into their lives-it was something they did to stay alive. Consequently we aren't very good at motivating ourselves to do it as we were when not running meant starving to death or being eaten by a sabertooth tiger. We struggle to get ourselves moving because the urgency simply isn't there.
Likewise we are not very good rejecting food,particularly delicious foods that we crave. Again, having too much food was a problem that few if any of our ancient ancestors would have faced on a regular basis-while starvation was a constant possibility. In the rare event that a smorgasbord was made available to our ancestors the extra fat reserves kept by the body would almost certainly have been burned off in a time when food became relatively scarce.
As bad as we are at exercise our capacity to deprive ourselves of food is even more dismal. It seems over the course of time our bodies did evolve some neurological rewards for running. When we run endorphins are released giving us an improved sense of well-being. But with food depravation just the opposite occurs. While depriving ourself of food does have benefits to the function of many of our organs, neurologically we are punished for it. Cortisol, a stress hormone, is released when we fast or reduce our caloric intake. This made sense for our ancestors-since it probably motivated them to look for food immediately since the time from when they started looking for food and when they actually found it would have often been quite long. However for modern humans this creates havock-reducing calories leads to stress that often leads to increased food consumption which then relieves the stress but leaves us overweight.
So our evolutionary past has clearly put us at a disadvantage in the battle of the bulge.
Subscribe to:
Posts (Atom)