As a highly social species,1 humans have an evolved tendency to favor the ‘in-group.’ This trait significantly impacts our immunity, or lack of it, to false or harmful information. The emerging science of cognitive immunology must take full account of this fact.

The Group Mind

Volunteers for a research study enter a room with other strangers. The researchers show slides of abstract paintings by two painters, Klee and Kandinsky, and ask each person to decide which painter's slides they prefer. They are then assigned to be a member of a group, supposedly based on their preferred painter, but in fact, randomly. There are now two arbitrary groups, one notionally based on liking Klee paintings, and the other preferring Kandinsky's.

These are called  'minimal groups' – meaning ones that have no purpose, past, or future. They are just arbitrary, transient groups to which a person temporarily belongs. These groups are different from most of the other ones we belong to in life. Our real groups have a purpose – family protection, soccer team victory, religious dominance, or national prestige, for example. Such groups have long histories, sometimes lasting hundreds of years, and rationales that usually involve trying to get a competitive advantage over other groups. They also have a strong sense of continuity into the future – our legacy as a political party, our nation's glorious future, the eternal light of our faith, the future of our family, etc.  

The world is wracked by the consequences of competition between groups that have purposes, pasts, and futures. Hindu versus Moslem in India, Catholic against Protestant in Ireland, Republican versus Democrats in the USA, and so on. One could even say that the history of humanity is the story of such groups and their conflicts.

But suddenly in this experiment, people find themselves in a completely arbitrary group with no history or common values or purpose, or future. Surely that makes the group irrelevant and unimportant? Apparently not; in 1971 a brilliant social psychologist at the University of Bristol called Henri Tajfel2 demonstrated what has come to be called the "minimal group effect.”

Tajfel and his colleagues discovered that merely belonging to a random group brought out a series of behaviors and attitudes that are eerily familiar throughout the human race. These are ingroup favoritism and outgroup discrimination. And here's a remarkable fact from this research: people allocate rewards to their ingroup and impose sanctions on the outgroup, even when the overall costs and benefits of their group-favoring choices are to everyone’s detriment!  In other words, the group mind inclines us to 'cut off our noses to spite our faces.'

This daunting fact arises from a situation where there is no competition between the Klees and Kandinskys. There is no zero-sum game in play here because the two groups are entirely without purpose or future. But there appears to be a primitive drive in the human mind to define oneself in a group instantly and then automatically favor that group at the expense of an outgroup. Why on earth does this happen – and can it help us understand how confidence operates in groups and nations?

A clue comes from a 2003 German study that used the Klee-Kandinsky minimal group method. They observed how much people favored their ingroup when allocating money.3 Cleverly, the researchers manipulated each person's individual confidence by telling them that they had performed poorly or well on a problem-solving test given previously.

Those told they had done badly became much more prejudiced against the outgroup and for their ingroup. Feeling bad about themselves,  in other words, made people more tribal.

The false feedback about their intelligence threatened their egos, and so as if in compensation, the collective ego of the ingroup offered some protection.

These findings may help explain the dramatic political changes in the UK and the USA in 2016.  If, as seems likely, the post-2008 recession caused millions to lose confidence, this would have made them more vulnerable to the ego-boosting comfort of ingroup favoritism, and its sinister twin, outgroup prejudice. That is arguably why millions flocked to populist causes built on distorted information: their mental immunity had been compromised.

Donald Trump in the USA, Nigel Farage in the UK, Marie Le Pen in France, and Matteo Salvini in Italy are all examples of this phenomenon.  People mobilized by populists embraced ingroup bias and outgroup prejudice because their confidence was eroded by feelings of having lost out.

The fuel for these political movements, however, wasn't just their ingroup mindset.  There was also a much more visceral, emotionally-laden consequence of ramped-up tribalism for these confidence-challenged millions. Research from Emory University in 2008 shows that simply being made to feel part of an arbitrary ingroup has a profound mood-enhancing effect on the brain's reward network.4 This, for the populist, is the equivalent of dispensing free anti-depressants to millions of followers.

And supporters of extreme ideologies are in greater need of such anti-depressants, 2019 research from Amsterdam's Free University showed. Supporters of the extreme right or left ideologies are more psychologically distressed than other people.5 The black-and-white thinking of extremist ideologies offers simple solutions to complex problems. This is attractive to people whose confidence and self-esteem are low. It also makes them more intolerant of other groups and overconfident about their judgments. Strong ingroup feelings and overconfidence both activate the brain's reward network. This helps alleviate the psychological distress of those captivated by the simple, misleading, and over-optimistic solutions dangled in front of them by extremists, messages that their minds’ defenses might have otherwise blocked.

Fear Undermines Mental Immunity

Fear represents another threat to our mind’s defenses. And the fear of our extinction seems especially potent.

On April 11th, 2020, a video was tweeted from a McDonald's restaurant in Guangzhou, China, showing black people not being allowed to enter the restaurant (6). A few weeks earlier, on February 24th in London's Oxford Street, a 23-year-old student from Singapore was attacked by a group of men. One of them said I don’t want your coronavirus in my country before smashing his fist into Jonathon Mok’s nose.7

These are just two examples from thousands across the world of how fears of covid19 infection during the 2020 pandemic prompted xenophobic aggression against people perceived to be from an outgroup – and hence a threat.

In 2014 another highly infectious disease, Ebola, mushroomed in West Africa. The blanket worldwide publicity kindled a widespread fear that it would spread to other countries such as the USA. Even though the chances of contracting Ebola in the USA were infinitesimally small, millions of people expressed fear of the disease. When researchers at the University of California at Santa Barbara surveyed a thousand Americans, they discovered that the more vulnerable people felt to Ebola, the more xenophobic they were in their attitudes to immigrants in general, and West Africans in particular.

When people are frightened, do they assuage their fear through the anxiety-reducing comfort of the ingroup, with its inevitable outgroup prejudice? Yes, they do, and this fear extends well beyond disease pandemics. Since validated over many continents and countries, one theory to explain this goes by the rather forbidding name of Terror Management Theory.9 

It can be upsetting and saddening if we are exposed to thoughts of death, and we do come across reminders of it from time to time. For example, people take part in an experiment where the researchers make them more aware of their mortality by asking questions like.  Please describe your emotions when thinking about your own death or What do you think happens to you when you are physically dead?

According to Terror Management Theory, being reminded of my mortality – for instance, in a global pandemic – triggers a set of responses in me that are mostly unconscious attempts to protect my ego – and with it my self-esteem – from a frightening awareness of its future extinction.

Hundreds of research studies over many scores of countries have confirmed that being reminded of death leads us to think, feel, and behave in very particular ways.10 Above all, it makes us rush to shore up self-esteem by committing ourselves more to our ingroup, its worldview, and the selective information about the world it provides. The purpose of this self-esteem is to shield us from the terror of our individual insignificance within the void of eternity, the theory goes.11

Reminded of our mortality, we suddenly strive, mostly unconsciously, to see ourselves as worthy vehicles for the ingroup values of our culture or political affiliation. This makes us feel some sort of continuity of the self as part of a broader virtue that we fervently desire to be part of. That sense of moral value gives our death-threatened self-esteem some symbolic immortality and threatens to overwhelm the antibody doubts that a mental immune system provides.

Most religions promise real, not symbolic, immortality to protect the ego against the terror of extinction. When thoughts of death tug at the edges of our consciousness, even the brains of the most devout show the typical response, and this psychological reaction has enormous political ramifications.

Take this 2007 University of Alberta study of Canadian students, for example.12 A group was selected for their strong pro-Canadian views. For example, they answered strongly agree to statements like Being Canadian is an important part of my self-worth or I am proud to be a Canadian. They were then split into two groups and given an article to read. Half read an anti-Canadian article by an American that mocked and criticized all things Canadian, such as its health system and the politeness of its citizens. The other half read a similarly negative article about Australia.

The students then played a word game where they had to fill in the letters of incomplete words on a page. Most only had one solution like W _ _ D O W (window) or P _ P _ R (paper). Cleverly, six of the words had at least two possible solutions, one of which was death-related and the other not. The word fragments were B U R _ _ D (buried or burned), D E _ _ (dead or deal), G R A _ _ (grave or grape), K I _ _ E D (killed or kissed), S K _ _ L (skull or skill) and C O F F _ _ (coffin or coffee).

The patriotic young Canadians who read the article demeaning their culture and national identity chose the death-related words more often than those reading the Australian text.  This supported the idea that our self-esteem – including our collective, national self-worth – operates as a sort of anti-anxiety drug soothing our fear of death.

Does it work the other way around? – Does boosting our self-esteem offer any protection against these disturbing thoughts of death? To find out if this was the case, volunteers in a 1992 University of Arizona study took a phony personality test. They then got fake feedback about their personality. This could be neutral  – some of your aspirations may be a little unrealistic. Or, it could be positive – most of your aspirations tend to be pretty realistic, or your personality is fundamentally strong.13

Half of each group then saw a video called Faces of Death, a documentary about the many different ways in which a person can die, including an actual autopsy. The remaining half of each group watched a neutral video with no death-related content.

That yielded four groups:

high self-esteem, watch death video;

neutral self-esteem watch death video;

high self-esteem watch neutral video;

neutral self-esteem watch neutral video.

The question was, did the boosted self-esteem quell the anxiety aroused by death thoughts?  Neither of the groups which had watched the neutral video became more anxious – each scored on average a normal 44 out of 80 on an anxiety questionnaire. But those with un-boosted self-esteem who watched the death film saw their anxiety spike to 54.

What about the death video watchers with bolstered self-esteem? They were untouched by the upsetting video, and their anxiety levels stayed low at 44. This finding supported the core idea of terror management theory. We work so hard to gain self-esteem and support for our worldview so as to ward off existential anxiety. And it works.

Such inklings of death at the fringes of consciousness also provoked more worrying reactions, a joint University of Colorado-Iran study in 2006 showed.14 Iranian university students were made more aware of their mortality by being asked to describe the emotions that thinking about their death aroused. They then read questionnaire responses supposedly written by fellow young Iranians on the subject of political martyrdom. Some of the answers supported suicide bombing (e.g., deaths in the name of Allah will bring an end to the imperialism practiced in the west). Others did not (e.g., human life is too valuable to be used as a means of producing change).

The students then rated how much they agreed with and liked the people who had answered the questionnaires. Respondents primed by thinking of their death rated the pro-suicide-bombing respondents more favorably. They also agreed with them more than did students who hadn't been made to think about their death. Their mental immunity to such messages, in other words, had been severely weakened.

These researchers then did a similar study with US students, who became more likely to support extreme military violence that could kill thousands of civilians, after thoughts of their personal death were kindled.

We have all seen distressing images of destroyed cities in Syrian and other wars. It turns out that merely viewing these images makes us more aware of our mortality, a 2012 University of Missouri study found. And because of this, we become more dogmatic about our worldview and more inclined to support military aggression or terrorism against the other.15 

So here is a sobering and vicious cycle – deadly conflict changes our brains to make that conflict worse. It does so by our fear of death inclining us to defend our worldview – including accepting distorted information - to protect our self-esteem. Canadian journalist Jessica Stern interviewed religious terrorists from different religions, including Hindu, Jewish, Muslim, and Christian. Her 2003 book concluded that they were motivated by damaged self-esteem caused by feelings of personal and communal humiliation.16

It can be hard for millions of people to feel part of a group, but one surefire way of making that happen is to remind them of their mortality through fear and threat. Just as a slight can diminish an individual's self-esteem, a slight can diminish the collective self-esteem of a population. And when this happens, it breaches an essential mental defense against the grim reaper. It makes people cleave to their tribe, dehumanize outsiders, and lower their immune defenses to false information about the world.

An expanded version of this article is available in my book How Confidence Works.17


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16.          Stern J, editor Terror in the Name of God2003: Ecco New York.

17.         Robertson I. How Confidence Works: The new science of self-belief: Penguin; 2021