The unexpected origins of our deepest beliefs
Our opinions are shaped less by reason than by an invisible web of forces — climate, geology, culture, biology, and genetics. Recognising this should make us more humble about our own views, and more empathetic toward those who hold different ones.
‘This book is always fascinating but frequently mind-blowing’
Marina Hyde
We did not choose most of what we believe.
We inherited it.
From the latitude at which our ancestors settled, to the language in which we first learned to think, to the particular twist of our DNA — an invisible web of forces assembled our worldview long before we were old enough to question it. Munthe’s book doesn’t argue that reason is useless. It argues that reason is rarer than we imagine, and that understanding this changes everything: how we talk to each other, how we govern ourselves, and how we hold our own opinions.
Long before you formed your first conscious opinion, these forces were already at work — assembling the architecture of what would feel, to you, like your own free thought. Click each to explore.
The "standard model" of opinion formation — Reason + Socialisation = Opinion — is correct but radically incomplete. Our opinions are also shaped by a host of non-rational "encumbrances": physical traits, brain shape, genes, climate, historical legacy, personality, and social function. Recognising these forces should produce both humility about our own views and empathy for those who hold different ones.
Read more →Climate shapes beliefs — not by numbing nerve endings (Montesquieu's discredited idea) but by selecting for cultural strategies that manage environmental threats. Hot, humid, pathogen-rich climates produce socially conservative, collectivist, hierarchical, and authoritarian cultures as a form of behavioural immunity. Extreme climates in general produce authoritarian politics and moralising religion. Climate variability, by contrast, produces cultural adaptability.
Read more →Geology and topography — operating through agriculture, land use, and settlement patterns — are root causes of political and philosophical difference. The physical world shapes how communities organise themselves, what values they develop, and ultimately what they believe. Some of the deepest cultural divides on earth (East/West individualism-collectivism, US regional politics, rural/urban divide) trace back to the soil.
Read more →Culture shapes not just explicit beliefs but the deepest, most invisible layers of our cognition: what we literally see, what emotions we are capable of feeling, what we value, and what we count as valid reasoning. Because this "deep culture" is invisible to us, we mistake our own culturally specific worldview for universal human nature — the error of paradigm blindness.
Read more →Our biology — the shape of our faces, the architecture of our brains, the density of our taste buds — predisposes our politics. Conservatives and liberals literally have different brains, respond to different stimuli, and inhabit different neurological realities. Because we start from different premises (even perceptual ones), we naturally arrive at different conclusions. Our political differences are not just intellectual; they are physical.
Read more →Genetics explains approximately 60% of the variance in our broad political orientation and substantial portions of our views on religion, economics, sexuality, and many other issues. Twin studies — especially Bouchard's Minnesota Study of Twins Reared Apart — establish this with precision. The correct formula is not "nature vs nurture" but "nature via nurture": genes predispose but never predetermine; they interact constantly with environment. Biologising politics is historically dangerous (eugenics), but recognising the genetic basis of attitudes may also make us more tolerant of difference.
Read more →Emotion is not the opposite of reason — it is a form of cognition. Damasio's "Elliot" case proved that people without emotional processing make catastrophically bad decisions despite intact IQ. Our moods measurably alter our beliefs: fear breeds pessimism, anger breeds tunnel vision and optimism, anxiety breeds conspiracy thinking and reduced empathy, disgust hardens moral judgement. Loneliness is the dominant political emotion of our time — it kills empathy, breeds aggression, and radicalises. We cannot address "emotional politics" through argument alone; we must address the underlying feelings.
Read more →We hold many beliefs not because they are true but because they perform vital social functions: signalling group membership, competing for status, managing anxiety, and justifying systems of power we depend on. The "strategic absurdity hypothesis" explains why religious and political beliefs are often unbelievable — being unbelievable is the point, it is a costly signal of commitment. Understanding beliefs as social tools rather than truth-claims radically changes how we should argue.
Read more →Left and right are not accidents of history or failures of understanding — they are biological phenotypes evolved for different threat environments, just like the wary and curious guppy fish. Politics is universal because it is always an answer to a small set of "bedrock dilemmas" about living together. Neither political phenotype is universally superior; both are adaptive under different conditions. We need both — like the Iroquois needed both sachems and warriors — and it is their constant cohabitation and conflict that makes civilisation possible.
Read more →Humans are poor reasoners alone but extraordinary reasoners in groups — because reasoning evolved not for individual truth-finding but for social persuasion. The "cognitive flaws" that make us terrible solo reasoners (confirmation bias, motivated reasoning) are the very tools that make collaborative reasoning work: my stubbornness forces you to produce better arguments. Argument is not a brawl; it is a collaborative act of reasoning, a "contact sport." The Wason puzzle solved alone: 80% failure. Solved in groups: 80% success.
Read more →The polarisation we see today arises from monism — the Enlightenment-inherited belief that there is one right answer in politics, and that those who disagree are corrupted versions of ourselves. Berlin's value pluralism is the correct frame: our values are genuinely incommensurable, our political phenotypes are natural, and neither side can be "right" in the absolute sense. The conclusion is not passivity — it is radical engagement. Our opponents are our intellectual collaborators; argument is the only tool we can trust.
Read more →Query the ideas, arguments and provocations at the heart of Why We Think What We Think. Powered by the book’s complete knowledge base.
A book that will leave you looking at your own opinions differently — with more curiosity, more humility, and a more generous eye for the invisible forces that shaped everyone around you too.
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