Sebastian Junger: All of the archeological and anthropological evidence from prehistory and current day hunter-gatherer societies shows that we’ve thought to live in small groups of 40-50 people, maybe 100-150 people. Those were the typical living sizes based on encampments that have been found and of course people living in those conditions today. The size of our brain seems to be correlated to groups of about that size when compared to other primate species. Clearly we live in a modern society and we organize ourselves in much larger groups. But our wiring, our evolutionary wiring seems to be backdated to a period of time some tens of thousands of years ago when we lived an existence of hunter-gatherers in a very harsh environment.
Our evolutionary design has a lot of implications for how we live in modern society and of course for how we conduct warfare. A platoon is around 40 or 50 soldiers not by coincidence. That’s around the size of a typical hunter-gatherer group in our evolutionary past. One of the things that soldiers find when they’re deployed in combat or even at a rear base is that they very naturally fall into a kind of communal existence with their platoon mates. They’re sleeping shoulder to shoulder. They’re eating meals together, doing missions and patrols together. They’re doing everything together. You’re never out of sight of another person. And you basically live for the group. There’s no individual survival outside of group survival in our evolutionary past and often in combat as well. Because we’re wired for that, because we evolved for that it feels very, very good when you experience that. And I’ve experienced it as a civilian reporter in a platoon. It feels instantly right. The only analogy I can think of is holding a baby in your arms for the first time. I just feels like oh my god, this is exactly what I’m supposed to be doing. This is right. And that kind of communal existence feels deeply correct and natural in the same way. And so when soldiers come back from deployment often they miss the war but what they really miss I believe is that communal connection. Not so much the combat and the killing of course – they’re not psychopaths, they’re just like the rest of us. But they do miss that communal connection because modern society is pretty much gone. And they don’t really notice that until they return to it.
One thing that interested me in researching my book Tribe was the high rates of PTSD, post-traumatic stress disorder, in the U.S. military. And estimates vary but they range as high as around 20 percent and much higher percentages than that claiming disability from it. In the Israeli military by contrast the rate is as low as one percent. PTSD is a hard thing to measure. That’s why there’s some variability. But it’s as low as one percent. It’s way lower than in the U.S. And I wanted to know why. They are roughly equivalent militaries, modern societies. What is the difference? And Israeli psychologists that I spoke with pointed to a couple of things. One was that the wars that Israel has fought in the last couple of generations have been like right on their doorstep. The Yom Kippur War of 1973 saw Israeli soldiers fighting literally on the outskirts of their own villages, fighting an invading army. And the psychological damage that comes from fighting in that kind of circumstances is greatly lessened as compared to traveling thousands and thousands of miles to fight a war that doesn’t seem to bear any relation to your home, to your country. It’s a distant affair that maybe doesn’t seem necessary sometimes.
The other difference between Israel and America is that Israel has mandatory military service. Roughly half of Israeli citizens serve in the military. So if you’re a soldier and you saw combat in Lebanon or whatever when you come home you’re coming home to a community where an enormous number of people were also in the military. So there really isn’t a transition from military to civilian life. It’s all blended. There’s a lot of civilian life in the military experience and vice versa. So that transition is easier and as a result the psychological consequences are diminished.
So the question is during a very fractured time in American society the gap between rich and poor is widening. We often live in racially segregated communities. There’s a really ugly vitriolic content to political discourse these days. There are politicians talking with real contempt about their president, segments of the population. When you have a country that’s in such a state of disrepair what can you do to bring it together? One possibility is mandatory national service with a military option. Personally I think it’s immoral to force someone to fight a war they don’t believe in. But mandatory national service would not just mean actually during war time. It would be continual. And it would allow young people to contribute to us all, contribute to this country without having to carry a gun. You could do it in many other positive ways and I think it would do enormous good not just for the young people themselves but also for this country as a whole.
This country doesn’t require anything of its citizens. And when you don’t have to invest in something you don’t value it. One of the advantages of mandatory national service is that it enforces an investment of a year or two by a young person in the collective good of this country. And when you do that you create value.
It takes all the races, all the social classes, everything, all the educational levels and it puts them in a big pot and stirs them up together and gives everyone the experience of investing in the collective good. The downside of course is that we’re in a very sort of anti-government state of mind right now in this country. And that there might be objections to it. One of the reasons we might be in an anti-government state of mind is precisely because no one in this country is required to spend any time at all contributing to the collective good. It’s a self- fulfilling prophecy. It’s a feedback loop. How do you break that feedback loop? Well you break it by changing the law. It will take courageous politicians who are willing to buck a national sentiment to do something good for the country. I think at some point politicians have to put their country before their careers and simply vote for what’s right in the long term.
The idea of cities may not be new, but they aren’t how things were always done. Back when people hunted and gathered from landmass to landmass, people lived in small groups of about 50 to maybe 150 members, according to Sebastian Junger, American journalist, author and documentarian.
It was very natural for humans to settle into these smaller groups. Human brains are wired to create small tribes, and our capacity hasn’t evolved for the large cities many of us tend to live in now. So it’s no coincidence that the army isn’t just one large sea of soldiers, it’s divided into smaller platoons averaging about 40 to 50 men. This number was a natural choice as it felt comfortable, satisfying the old hunting-gathering needs that still tick inside modern-day humans.
Platoons abide by the old wiring in human brains, which allows soldier to quickly, neatly, and naturally fall into a "communal existence," as Junger says. Platoons do almost everything together, from fighting, to sleeping, to eating.
This is what many of soldiers miss when they come back from war. They don’t miss the violence and life or death situations, but the community that being in a platoon creates.
One thing Junger focuses on in his latest book Tribe is the incidence of Post-Traumatic Stress Disorder. PTSD is very hard to measure, meaning it’s hard to precisely quantify how many soldiers have it and how many don’t. But for an interesting and telling comparison, the rate of PTSD in the Israeli military that is roughly 1%. In the American military, it’s closer to 20%. Even with all variables considered, that’s a huge difference.
Junger sought the explanations for these figures and among them were two key factors. Most of the Israeli wars are fought close to home, including the Yom Kippur war, where many soldiers could walk home from the battles. And unlike in the United States, Israel’s mandatory service law means that when young soldiers come home to their cities, more than half of the population understands what they’ve been through, because their neighbors, parents, and friends from school have all been in the service. American soldiers come home to a society that generally can’t relate - their experience leaves them isolated.
While he believes it’s unethical to make people fight in any war, Junger is an advocate for mandatory national service in the US, with non-military options. There are many ways to contribute to society that don’t involve taking up arms. And perhaps with a higher rate of shared experience and many more small tribes of people who come together for a year or two, from all races, classes and walks of life, it could build a stronger country and bridge the immense divides within American society.
Sebastian Junger's book is Tribe.
- A study provides further confirmation that a prolonged lack of sleep can result in early mortality.
- Surprisingly, the direct cause seems to be a buildup of Reactive Oxygen Species in the gut produced by sleeplessness.
- When the buildup is neutralized, a normal lifespan is restored.
We don't have to tell you what it feels like when you don't get enough sleep. A night or two of that can be miserable; long-term sleeplessness is out-and-out debilitating. Though we know from personal experience that we need sleep — our cognitive, metabolic, cardiovascular, and immune functioning depend on it — a lack of it does more than just make you feel like you want to die. It can actually kill you, according to study of rats published in 1989. But why?
A new study answers that question, and in an unexpected way. It appears that the sleeplessness/death connection has nothing to do with the brain or nervous system as many have assumed — it happens in your gut. Equally amazing, the study's authors were able to reverse the ill effects with antioxidants.
The study, from researchers at Harvard Medical School (HMS), is published in the journal Cell.
An unexpected culprit
The new research examines the mechanisms at play in sleep-deprived fruit flies and in mice — long-term sleep-deprivation experiments with humans are considered ethically iffy.
What the scientists found is that death from sleep deprivation is always preceded by a buildup of Reactive Oxygen Species (ROS) in the gut. These are not, as their name implies, living organisms. ROS are reactive molecules that are part of the immune system's response to invading microbes, and recent research suggests they're paradoxically key players in normal cell signal transduction and cell cycling as well. However, having an excess of ROS leads to oxidative stress, which is linked to "macromolecular damage and is implicated in various disease states such as atherosclerosis, diabetes, cancer, neurodegeneration, and aging." To prevent this, cellular defenses typically maintain a balance between ROS production and removal.
"We took an unbiased approach and searched throughout the body for indicators of damage from sleep deprivation," says senior study author Dragana Rogulja, admitting, "We were surprised to find it was the gut that plays a key role in causing death." The accumulation occurred in both sleep-deprived fruit flies and mice.
"Even more surprising," Rogulja recalls, "we found that premature death could be prevented. Each morning, we would all gather around to look at the flies, with disbelief to be honest. What we saw is that every time we could neutralize ROS in the gut, we could rescue the flies." Fruit flies given any of 11 antioxidant compounds — including melatonin, lipoic acid and NAD — that neutralize ROS buildups remained active and lived a normal length of time in spite of sleep deprivation. (The researchers note that these antioxidants did not extend the lifespans of non-sleep deprived control subjects.)
Image source: Tomasz Klejdysz/Shutterstock/Big Think
The experiments
The study's tests were managed by co-first authors Alexandra Vaccaro and Yosef Kaplan Dor, both research fellows at HMS.
You may wonder how you compel a fruit fly to sleep, or for that matter, how you keep one awake. The researchers ascertained that fruit flies doze off in response to being shaken, and thus were the control subjects induced to snooze in their individual, warmed tubes. Each subject occupied its own 29 °C (84F) tube.
For their sleepless cohort, fruit flies were genetically manipulated to express a heat-sensitive protein in specific neurons. These neurons are known to suppress sleep, and did so — the fruit flies' activity levels, or lack thereof, were tracked using infrared beams.
Starting at Day 10 of sleep deprivation, fruit flies began dying, with all of them dead by Day 20. Control flies lived up to 40 days.
The scientists sought out markers that would indicate cell damage in their sleepless subjects. They saw no difference in brain tissue and elsewhere between the well-rested and sleep-deprived fruit flies, with the exception of one fruit fly.
However, in the guts of sleep-deprived fruit flies was a massive accumulation of ROS, which peaked around Day 10. Says Vaccaro, "We found that sleep-deprived flies were dying at the same pace, every time, and when we looked at markers of cell damage and death, the one tissue that really stood out was the gut." She adds, "I remember when we did the first experiment, you could immediately tell under the microscope that there was a striking difference. That almost never happens in lab research."
The experiments were repeated with mice who were gently kept awake for five days. Again, ROS built up over time in their small and large intestines but nowhere else.
As noted above, the administering of antioxidants alleviated the effect of the ROS buildup. In addition, flies that were modified to overproduce gut antioxidant enzymes were found to be immune to the damaging effects of sleep deprivation.
The research leaves some important questions unanswered. Says Kaplan Dor, "We still don't know why sleep loss causes ROS accumulation in the gut, and why this is lethal." He hypothesizes, "Sleep deprivation could directly affect the gut, but the trigger may also originate in the brain. Similarly, death could be due to damage in the gut or because high levels of ROS have systemic effects, or some combination of these."
The HMS researchers are now investigating the chemical pathways by which sleep-deprivation triggers the ROS buildup, and the means by which the ROS wreak cell havoc.
"We need to understand the biology of how sleep deprivation damages the body so that we can find ways to prevent this harm," says Rogulja.
Referring to the value of this study to humans, she notes,"So many of us are chronically sleep deprived. Even if we know staying up late every night is bad, we still do it. We believe we've identified a central issue that, when eliminated, allows for survival without sleep, at least in fruit flies."
