Nature, we are told, equipped us with all sorts of instincts to help us survive. However, most of them just get us into trouble. Especially the fear response ones. It's true that we live in a very different world than the primates who evolved these responses, but often what we do when we're afraid doesn't seem to make sense even in nature. Let's take a look at why we're cursed with some lousy responses to everyday scares.
Humans are social creatures. That's why we keep grouping together in big cities even though we clearly hate each other. Exploding into a ball of salty liquid is no good when you are trying to tell a harmless little social lie like claiming you didn't ding the car door of the big angry man with the baseball bat. And yet there's always the general adrenal response. When people get nervous their body causes them to increase their heart rate so they can run and dilate their pupils so they can see, and sweat like hogs, so they don't overheat. Of course, we can't out-see wolves, or out-run bears, so we're pretty much just pre-salting ourselves for them. Perhaps we're trying to slowly kill our predators via high sodium intake?
But there could be another reason. Contrary to popular belief, dogs and horses and bees can't smell human fear, but humans can. What's more, this scent causes humans themselves to be afraid. Perhaps sweating like a marathon runner is a way to signal your unease to the people around you. Or perhaps, since fear is contagious, this is some small way in which you can trigger fear in the large gentleman with the bat in front of you.
All right. I'll admit it. This one is personal. I have pale skin and an apparently fantastic array of capillaries that kick into gear at a moment's notice. Blushing doesn't sway our wild predators or our civilized ones. What's more, the whole thing is a dirty trick by the adrenal system. When the slightest problem pops up, it goes into the aforementioned adrenal response, including dilating blood vessels to get more blood and oxygent through the body. Fair enough. But what's making your - or, just as an example, my - face red isn't essential arteries. It's veins. And veins don't usually respond to the adrenal response. The ones in your face make an exception for extreme humiliation. So it's not a way to keep you alive. It's just a way to see you suffer. The leading theory is that blushing is a purely social response. It's a non-verbal way to show we screwed up, if only in our own minds. And if you have the type of nervous mind that thinks it screwed up a lot, enjoy your red face. Everyone else will.
What better way to respond to a stressful emergency than by making a sound like a fire engine and evacuating all the liquid in your face? Sniveling and hiccuping your way through an explanation of why you shouldn't be punished is sure to work on everything from modern traffic cops to ancient sabre toothed tigers. Seriously - why do we do this? The truth is, there are a lot of potential reasons. Research shows that emotional tears contain large amounts of hormones that would otherwise be in the body, increasing stress even further. So tears might be an evacuation route for fear and a way for people to calm themselves. A recent study showed that women's tears lowered the testosterone level of men who smelled them. Scientists think that this might have helped women fend off unwanted advances. A caveman keeps bothering the wrong cavewoman for him, and suddenly there's snot everywhere and she smells funky.
7. Throwing up
In Australia, a thief got so nervous during a robbery that he threw up. The vomit contained DNA, it was tested, and he was convicted. Polar bears are a lot less sympathetic than juries. How does throwing up all over ourselves help anyone? It looks like throwing up is part of the body's go-to response for stress, poisoning, head injuries, sickness, dehydration, and pretty much anything else. There are some noises about how throwing up makes people lighter, how it keeps them from cramping if they have to run after a meal, and how it might put off predators. Mostly, though, it's the only way the body knows how to respond when we feel crappy.
Although, it seems there is something called fecal vomiting. It's when the muscles around the lower intestine cramp up so hard that they squirt fecal matter into the stomach, which then ejects it through the mouth. I'm willing to bet even bears wouldn't want to eat something covered in that. So that might help people survive, although the cost hardly seems worth it.
6. Nervous laughter or smiling
Ah, this is the grotesque response we've seen in a million politicians, beauty pageant contestants, and reality TV show victims. They get horrible, horrible news, and they begin to smile. And you can tell, just looking, that they can't help it. This is painful for everyone. Why, biology? Why do this?
Some psychologists say that laughter is a good defensive strategy, and helps release the tension in the body, but that hardly applies in a situation like that. Those people aren't trying to convince themselves they're fine, they're trying to convince everyone else that things are fine. Laughing during tension is a social signal that lets those around know that they don't have to pay attention, since everything is fine. It's thought to be a way to dispel potentially dangerous group scenarios. A way of saying, "Nothing to see here. Move along. Certainly don't join in the mob attacking me." I wonder if it worked, even then.
4. and 5. Peeing and Pooing
Well, just to start with, no modern situation is helped by wetting the rug beneath you, but even back in the stone age, when people didn't wear underwear or have expensive carpeting, how would evacuating everything south of the belt make a frightening situation better?
Did you know that you could be carrying as much as eight pounds of 'waste' on you right now? No? Then what a delightful new fact you learned today! And if you're getting chased by wolves, it's nice to know that you and your extra eight pounds will be sprinting away from the oncoming pack as best you can. Unless you get rid of that extra weight . . . somehow. While everyone agrees that people wet themselves at the slightest provocation (How many of you did when you saw the redesign, for example?), sneaking some of that extra weight out the back end is often made even harder by fear. The adrenal response diverts blood away from the stomach and lower intestines, hindering digestion. So unless the poop is right next to the rectum, it can't come out. For those of you who managed it, in a particularly stressful moment, rest assured that accomplishing such a feat could be thought of as a sign of bravery. Pat yourselves on the back, you brave, smelly bastards! Just don't pat yourself anywhere lower.
Most motorists in rural areas have mowed down enough rabbits and deer to recognize the freeze response. Yes, staying still is a helpful tool in survival. Freezing is not. Staying still means choosing not to move. Freezing means not being able to move, think, or respond. That can't be helpful in any situation. There are a couple of theories on why mammals have a freeze response. Some say that it's a last ditch effort, after flight has failed, to feign death and be left alone. Others say it's a first response to a sudden threat. The moment something happens we freeze. We take in all possible information, and keep still so whatever it is doesn't notice us, and then we respond. If whatever it was happened to be so close that it got to us before the freeze response was over, it would probably have killed us anyway. The freeze response can be overcome with training, as long as the brain has healthy intercalated cells. These cells, housed in the amygdala, are resonsible for 'extinction memories'. They are what trains to brain to recognized that what it once thought of as an overwhelming threat can actually be dealt with. Animals that have damaged intercalated cells can't be trained out of the freeze response, and will always see certain things as a threat.
I mean. Just. What the hell?
Goosbumps are part of the overall muscle response. When the body gets a massive shot of adrenaline, the muscles tense up. To keep them pumped, the body also puts out a tempting buffet of glucose for them to burn. Between the two, every muscle in the body is working and active, including the tiny ones that make body hair stand up when it's cold. Each little muscle beneath the skin pulls the hair upright, and with it comes some of the skin, creating goosebumps.
There is one time when fainting is helpful. When you're a novelist, and you need to end a suspenseful scene on a dramatic note, you have your point of view character pass out and end the chapter. Other than that, it's total crap as a reflex. Many people think it isn't even a reflex, it's a social response. The Victorian era had many accounts of women swooning when an argument got too heated. Not that many ladies take a header into the ground during political debates anymore, and biology doesn't work that fast, so some social aspects of the behavior have to considered.
But some people do faint when they get too stressed. What, if any, help would that be? The technical term for this kind of fainting is vasal syncope. Blood pressure drops, and heart rate slows. Some say that it's a response to direct aggression from other humans. Fainting during dangerous fights or wars could be a way to signal that you're not a threat and get people to leave you alone. But there are plenty of animals that play dead without actually losing consciousness. A more likely explanation is hooked into why so many people keel over at the sight of blood. When blood pressure drops and heart rate slows, bleeding slows. Meanwhile, clotting continues just fine. Fainting quickly may be nature's version of triage. Shove everything else aside, and deal with the one major problem right away.
Via GibbsMagazine, Daily Beast, The Daily Telegraph, How Stuff Works, The Telegraph, Psychology Today, The Poop Report, My Shrink, How Stuff Works, and MSNBC.