I am an extremist. Not violent or murderous, but an extremist nonetheless. And so, I daresay, is nearly everyone reading this. Evolutionary scientists such as myself have recently been joining sociologists, political scientists, and psychologists trying to understand the origin of extremism. For us, the question arises: assuming that evolution by natural selection is in some way responsible for the fundamental outlines of human behavior, what is the adaptive value of behavior that places one’s self outside the mainstream, sometimes so far as to constitute a danger to self and others? Insofar as a genetic predilection in that direction would necessarily render any contributing genes less likely to be projected into the future, natural selection should have eliminated such genes and their associated tendencies from our species repertoire. And yet, extremism of some sort is sufficiently widespread as to be (oxymoronically perhaps) surprisingly common.

Here is a possible explanation that to my knowledge has not previously been floated: what is widely seen as extremism is not qualitatively discontinuous from normal, healthy, highly adaptive behavior found in other circumstances, albeit manifested in different ways. It is just somewhat more, well, extreme, and directed toward the larger world beyond its narrow, more praiseworthy orientation. For context, let’s take a short digression into the evolutionary world of selfish genery.

Richard Dawkins’s well-known construct of the “selfish gene” is widely accepted among evolutionary biologists, even as it is often misunderstood by the public. Selfishness, in this case, is a trope. The same fundamental aspect of natural selection could as well have been labeled altruistic because when benefitting others, notably genetic relatives, it speaks to the evolutionary imperative whereby what is selfish at the level of genes (because those others being assisted contain identical copies of the genes in question) is manifested as altruistic at the level of bodies: helping others without apparent personal payoff.

The most intuitive example of this process, so obvious it is often missed, is reproduction. In most cases, there is no immediate biological advantage derived by becoming a parent; the ultimate and only evolutionary explanation for reproduction is that making children and then caring for them is the most straight-forward way that parental genes can get copies of themselves catapulted into the future. Call it selfish or altruistic; it doesn’t matter.

Strongly affiliative behavior is in any event strongly selected for, especially when it comes to caring for offspring and other close relatives. In that sense alone, nearly everyone is an extremist, powerfully inclined to work and, if necessary, to sacrifice one’s self (in varying degrees) on behalf of a generally small circle of others. The biology of such commitment has been well studied, extending outward from extreme affiliation within one’s close relationships and proceeding outward, generally with decreasing intensity in proportion as the feltwork of genetic connection becomes less dense and therefore less compelling. Other motivating biological factors for powerful self-abnegating commitment have also been identified, including establishing and maintaining networks of reciprocity, achieving a reputation of being especially benevolent and thus worthy of admiration and assistance from others, and even – although I doubt it – possibly helping advance the interests of one’s group.

How might such a near-universal penchant for altruistic efforts and occasional self-sacrifice morph into what is widely acknowledged to be “extremism”? For starters, consider the bromide “One person’s terrorist is another’s freedom fighter” and substitute “fitness maximizer” for “freedom fighter,” and “extremist” for “terrorist.” I am no terrorist, but my concerns go beyond devotion to family, embracing an extreme commitment to social justice, environmental protection and especially nuclear abolitionism. Going farther than many others is not unique to the political left: during his 1964 Presidential campaign, Barry Goldwater used the slogan “Extremism in defense of liberty is no vice. And moderation in the pursuit of justice is no virtue!”

But extremism is not merely a question of differing subjective perceptions and thus, labels. Its origin likely involves the fact that most biological characteristics are distributed according to a bell-shaped curve, which means that most traits are especially frequent in moderate quantity, with their frequency decreasing at either extreme. When the total population is high – as with human numbers – the result is that even statistically rare traits can be present in rather high absolute numbers. In turn, just as some individuals, as part of their position on the altruism-caring-commitment continuum, show very little personal involvement with others, a comparable number could well show hyper-involvement; i.e., extremism.

This outcome does not conflict with the generalization that evolution tends to produce adaptive traits, even though in cases such as violent extremism, the result is maladaptive for the affected individuals as well as for the society of which they are members. Practitioners of Darwinian medicine have emphasized that such evolutionary misfires are made even more likely because of the payoff usually associated with correct functioning combined with the fact that nothing in the biological world works perfectly. There can be too much of a good thing: A strong immune system is necessary for health, but in some individuals, the system overshoots and produces auto-immune diseases. Fever helps fight many pathogens, but excessive fever can be deadly. Evolutionary psychiatrist Dr. Randy Nesse has suggested the “smoke alarm principle,” whereby we accept (albeit grudgingly) a certain amount of false alarms when we burn the toast because of the benefit of being warned if there is a genuine fire. Perhaps extremism is a warning signal for the rest of society. More likely, it is a predictable consequence of a widespread and adaptive tendency, like a smoke alarm, functioning at an extreme end.

Nothing in this discussion should be taken as excusing violent extremism. Nor does it claim to be a unitary explanation for commitment, whether extreme or moderate, to social or political causes. The roots of behavior are always diverse and interlocking.  Accordingly, in order to better understand the sources of extremism, we may well need to look not only at the evils perpetrated by the likes of Osama bin Laden but also at some of the more admirable (and comprehensible) aspects of ourselves.

Read the full series “Extremism in Historical and Evolutionary Perspective”:

  1. Introduction by Anthony Lopez and Hammad Sheikh
  2. The Virtue of Extremism is its Enhancement of the Ordinary by David Barash
  3. Extremism as Defense by Rose McDermott
  4. Why Extremism Isn’t the Real Issue by Mark Sedgwick
  5. What is Radicalization? by Sophia Moskalenko
  6. Conservative Extremists Are Afraid of Threats That Don’t Exist by Colin Holbrook and Jennifer Hahn-Holbrook
  7. Extremist Violence Has Its Roots in Morality, Not Ideology by Clark McCauley
  8. In the Eye of the Beholder: Parochial Altruism, Radicalization, and Extremism by Zoey Reeve
  9. Hidden Figures: The Untold Story of Terrorist Recruiters by John Horgan and Katerina Papatheodorou
  10. Why Terrorists Are Misunderstood by Max Abrahms
  11. Why Religious Extremism is Maladaptive by Richard Sosis
  12. The Extremist in Historical Perspective: Lessons from the Era of Anarchist Terrorism by Randall Law
  13. Terrorism and the Apocalyptic by Charles B. Strozier
  14. Extremist Groups Require the Greatest Trust Among Members by Melissa McDonald
  15. Moral Rigidity Evolved to Strengthen Bonds Within Groups by Antoine Marie
  16. Sacred Values, Social Identities, and Extremist Violence by Nafees Hamid


Published On: December 11, 2019

David Barash

David Barash

David P. Barash – Ph.D., University of Wisconsin, animal behavior and evolutionary genetics – is professor emeritus of psychology at the University of Washington, where he taught from 1973 – 2017. He is the author of more than 200 peer-reviewed papers, numerous op-eds and other articles in on-line journals, and author, co-author or editor of 40 books, most recently Through a Glass Brightly: Using Science To See Our Species As We Really Are (Oxford University Press, 2018), co-author with Judith Eve Lipton of Strength Through Peace: How demilitarization Led To Peace and Happiness in Costa Rica, and What the Rest of the World Can Learn From A Tiny, Tropical Nation. (Oxford University Press, 2018), as well as Approaches to Peace 4th ed. (Oxford University Press, 2018) and co-author with Charles Webel of Peace and Conflict Studies 4th ed. (Sage Publications, 2018).     


One Comment

  • Peter van den Engel says:

    Extremism is a psycholgical state and the lived spacetime equation creates a psychology: meaning higher or lower chance in relation to survival (not litterally), so the lower chance is surpressed.
    Being surpressed calls for a contrary reaction.

    Al of this has (almost) nothing to do with genes. But with consciousness.
    Since it is an abstract random quantum equation, It depends on how conflicting circumstances are/ or on how serious they are taken in what worldview.
    In general however extremism will never exist in non conflicting circumstances.

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