Tribalism goes to the core of who we are as human beings, and what we need to feel human. Yet modern society, by design, is anti-tribal. As Sebastian Junger argues in his excellent book, Tribe: On Homecoming and Belonging: “Modern society has perfected the art of making people not feel necessary.”
But let us first define our terms. The meaning of tribal tends to be pejorative, insofar as it refers to people who reflexively distrust those from other groups; those who 
attack others for their differences: be they of opinion, or colour, or culture, or preference. When I defend tribalism, I’m not defending this small-mindedness.
(Click the PDF icon, upper right, if you prefer reading a black-on-white script)
Rather, as Sebastian Junger argues, the tribe was the first and most fundamental form of human society. From these origins, human beings evolved to require three basic things in order to be content: “to feel competent at what they do… to feel authentic in their lives… [and] to feel connected to others. These values are considered “intrinsic” to human happiness and far outweigh “extrinsic” values such as beauty, money, and status.”
That is, we have a basic need to be good at our jobs, and for those jobs to have meaning. We also instinctively dislike societies that are too unequal. Junger uses the example of public defenders versus high-flying corporate lawyers. Studies have shown that wealthy lawyers have far higher rates of depression, and, in general, public defenders are happier people. Both may be competent at their jobs, but the high-flying lawyer is disconnected from the tribe by wealth, and by a form of work most in society distrust or outright detest.
From an evolutionary perspective, inequality and meaningless jobs would have meant the end of the tribe (or rather, there were no meaningless jobs in the historical tribe). While there was a tribal chieftain, if this person gathered personal power at the expense of others, they were soon removed by the rest of the community. Put simply, a leader who put the interests of the self above the tribe was an existential liability. Whereas today, in particular the West, the individual who puts the interests of the self above the community is often valorised.
Junger quotes from The Journal of Affective Disorders, which sums up the problem of modern society as such: “In effect, humans have dragged a body with a long hominoid history into an overfed, malnourished, sedentary, sunlight-deficient, sleep-deprived, competitive, inequitable, and socially-isolating environment with dire consequences.”
Junger begins his short book by recounting how settlers to the US would flee and join the Indian Tribes, but the opposite almost never happened. In cases where some 
settlers were kidnapped by Native Americans, often they would refuse to return even when they were rescued. It is from this premise that the rest of his argument unfurls, and it is one I found compelling: that the basic human needs of connection, competence, and meaning are harder to fulfil in the modern world.
Sebastian Junger has experienced war through his work as a journalist and documentary film maker. His doco, Restrepo, about a unit in one of the most dangerous parts of Afghanistan during the war, is a compelling insight into the acute stresses and comradeship of a military unit in wartime. He draws on this experience throughout the book, including the idea that the military unit is a microcosm of the tribe. Each soldier is trained to be good at what they do; each soldier is needed by the rest of the unit to perform their job well, and there is no differentiation between the troops based on colour, creed, or politics.
Junger notes that there is far higher prevalence of PTSD among US soldiers compared to those from many other countries. In the US, 12 to 20 per cent of veterans have PTSD today, including those who served as far back as the Vietnam War. Yet in the Israeli military, the rates are as low as 1%. Why? Because PTSD is, in part, a disorder of recovery. In Israel, the public – and the soldiers – know exactly what they are fighting for. They have compulsory national service, and many of the surrounding countries wish to see Israel wiped off the map. As such, there is ‘shared public meaning’ regarding the role and purpose of the soldier.
For US soldiers, on the other hand, according to Junger: “when they come home they realise that the tribe they were actually fighting for wasn’t their country, it was their unit.” So US soldiers, in this example, return home to a society that does not understand the sacrifices they made, to jobs that don’t feel real or necessary, and to a country that is toxically polarized and unequal.
Aid workers can have analogous experiences to soldiers. While they are not fighting, they are often in combat situations. If they are not in combat situations, they may be serving in the aftermath of a natural disaster, where death and tragedy infuses their day-to-day work. While rates of PTSD are high among aid workers (second only to the military), often it is the return home they often find most difficult.
Junger notes that: “One study found that one in four Peace Corps volunteers reported experiencing significant depression after their return home, and that figure more than doubled for people who had been evacuated from their host country during wartime or some other kind of emergency.” That is, while the work itself can cause PTSD (I personally know many aid workers who suffer from this), the return home can either prolong the trauma, or cause depression, because they are no longer able to do meaningful work.
Junger illustrates this via a poem by Siegfried Sassoon, who laments the loss of meaning on his return home for World War I:
In bitter safety I awake, unfriended
And while the dawn begins with slashing rain
I think of the Battalion in the mud
This loss of meaning happened to me after I returned from Mongolia as a volunteer 
from the Youth Ambassador Program (the Australian equivalent of Peace Corps). And again after returning from three years in Laos. I was witness to some terrible things: an ‘asylum’ for the mentally ill in rural Mongolia, for example, haunted me for some time*. The inmates were adults and children mixed together, 25% of the patients would die every year (from either starvation or the cold), and all variety of horrors were visited upon the kids. It was a fucking death camp.
Yet while I struggled with many of the things I saw, it was the return home to Australia that caused me to fall into a depression. I found the concerns of friends quite trivial, conversations predictable and unimportant, the stories in the news pathetic. I was depressed because there were no challenges; I was depressed because I came back to a society that could get on just fine without any contribution from me. My tribe was indifferent to my existence. As soon as my tribe no longer needs me, or any one person, it no longer is a tribe.
Junger quotes a former peace corps volunteer who says, of the modern world: “we are not good to each other. Our tribalism is to an extremely narrow group of people: our 
children, our spouse, maybe our parents. Our society is alienating, technical, cold and mystifying. Our fundamental desire, as human beings, is to be close to others, and our society does not allow for that.”
So there are two forms of tribalism, I think, positive and negative. The latter is expressed through racism, through in-group / out-group thinking. It manifests itself in the toxic culture of online politics, Woke V the Right.
Positive tribalism, of the kind discussed in Junger’s short book, is a type worth defending. As he says: “Solidarity is at the core of what it means to be human.” In our modern, atomised, unequal world, this meaning is harder and harder to grasp.
* I don’t have space for the full context and explanation of what happened in that place. If I’m being honest, I still don’t want to talk about it, nearly 20 years later. Suffice to say here that through the combined efforts of a Catholic Nun, a Buddhist Nun, the UK Ambassador, and my journalistic work in the local paper, we got the children out.