On Humans

“What do you think of the paleo diet?”
To my surprise, this has become the most common question I get after telling people that I cover human evolution. I’ve long struggled to answer.
Yes, the idea makes a lot of sense: humans evolved as hunter-gatherers, so our bodies should do well when we eat like hunter-gatherers.
But what exactly do hunter-gatherers eat?
Harvard professor Daniel Lieberman wanted to find out. After reviewing the evidence we have on the diets of hunter-gatherers, he came to a surprising conclusion.
“Not a single one of them eats the paleo diet”, he says.
Some hunter-gatherers eat more meat than the paleo diet prescribes; most eat much less. Plenty of them eat legumes and cereals, both of which are banned by paleo cookbooks.
“There is no one paleo diet,” Lieberman concludes. “The unique thing about humans is that we evolved to eat almost everything.”
Instead of fixating on a single “true” diet, Lieberman’s new book, Fed Up, offers a tour of the dietary history of humanity, discussing what lessons we can learn along the way.
In this episode, we cover the sweeping story of food and cooking, from the first chefs who processed food with stone tools to the explosion of ultra-processed foods during Lieberman’s own lifetime. Along the way, Lieberman offers insightful comparisons between humans and chimpanzees and discusses the many ways in which farming has — and has not — affected the human condition. He also explains why humans have always been “a very fat ape”, and what his experience of racing against horses tells us about the quirks of human evolution.
Towards the end of the episode, we also evaluate the pros and the cons of the modern food system. We finish with Lieberman’s deeply compassionate advice to all who would like to find a healthier lifestyle amidst the many challenges of industrial modernity.
Enjoy!

FACT-CHECKING
No factual errors have been detected yet. If you find a factual error, please leave a comment in the extended show notes (link below)

LINKS
Full show notes (uploaded within one hour): OnHumans.Substack.com
Support: Patreon.com/OnHumans

KEYWORDS
Ethnic groups & technical terms
The Hadza | Inuit | Agta | Homo erectus | Australopithecines | Lucy | Olduvai Hominid OH 8 | Oldowan stone tools | the Nandi Hills
Topics covered
Human evolution | evolutionary anthropology | human origins | big history | palaeoanthropology | paleo diet | hunter-gatherer studies | meat eating | persistence hunting | endurance running | sweating | human body fat | origins of cooking | origins of food processing | agriculture | neolithic revolution | peasant diets | famines | infectious disease | Mediterranean diet | ultra-processed foods | fibre | saturated and unsaturated fats | obesity | insulin resistance | type 2 diabetes | GLUT4 transporters | exercise | weight maintenance |
Music credit: Aleksey Chistilin (Lexin_Music) via Pixabay.

We can decide to stay home, but even then, the wider world is always close to our skin. From global trade to ideas that travel across continents, the wider world is always woven into our modern life.
Since when has this been the case?
There is a modern story about globalisation — a story about telecommunications and aeroplanes and such — but this is the climax of a long process, not its beginning. To find the deeper roots of globalisation, we should turn our gaze to the medieval world, and specifically to events around the year 1000.
Or so argues historian Valerie Hansen.
In this episode, we discuss the various curious developments around the year 1000 that began to connect the world into an interconnected web. From Viking explorers to the Silk Roads in Africa, Hansen offers many fascinating windows into the surprising connections that were already beginning to link the medieval world together. We also discuss the spread of inventions and world religions, as well as the deeper forces that Hansen thinks have long been driving world history.
Enjoy!

FACT-CHECKING
No errors have been detected in this conversation. If you notice one, please get in touch via Substack or the form below.

LINKS
Hansen's books: The Silk Road: A New History ⁠and ⁠The Year 1000.
Support: ⁠⁠⁠⁠Patreon.com/OnHumans⁠⁠⁠⁠
Articles & newsletter: ⁠⁠⁠⁠OnHumans.Substack.com⁠⁠⁠⁠
Get in touch: ⁠⁠⁠⁠https://forms.gle/h5wcmefuwvD6asos8⁠⁠⁠⁠

KEYWORDS
Names: Erik the Red | Bjarni Herjólfsson | Jacques Cartier | Vladimir the Great | Mansa Musa | William Dalrymple | Kenneth Pomeranz | Andrés Moreno-Estrada | Michael Coe | Mary Miller | Ralph Austen | Richard Davis | Paul Freedman | Thor Heyerdahl
Historical places: L’Anse aux Meadows | Greenland | Newfoundland | Chichén Itzá | the Yucatán Peninsula | the Baltic Sea | the Song dynasty | the Liao dynasty | the Abbasid Caliphate | Baghdad | the Indian Ocean | the Swahili Coast | Mali | Kaifeng | Hagia Sophia
Topics covered: Global history | macrohistory | economic history | medieval history | early global trade | long-distance trade | Silk Roads | Indian Ocean trade | trans-Saharan trade | maritime trade networks | Viking / Norse exploration | Polynesian migrations | population genetics | pre-Columbian contact | Viking–Maya contact hypothesis | Polynesian–Native American contact hypothesis | Song dynasty | Liao dynasty | Abbasid Caliphate | medieval Africa | Swahili Coast trade | medieval slavery | trans-Saharan slave trade | slavery and serfdom | slavery in China | spread of world religions | Christianisation of Europe | spread of Islam | Buddhism in Asia | diffusion of technology | history of inventions | paper, printing, gunpowder and the compass | Indian numerals and zero | Maya mathematics | history of food
Music credit: Aleksey Chistilin (Lexin_Music) via Pixabay.

How old is war? Does it stretch deep into human origins, or did warfare become common only as growing populations settled down? 
In Part II of this conversation with Douglas P. Fry, we return to the long-running debate about the origins of war.
Fry revisits his argument that aggression is ancient, but war is not. I put that claim to the test, raising some of the strongest objections from archaeology and the study of modern hunter-gatherers. We discuss Jebel Sahaba, nomadic and settled foragers, food storage, marine resources, population growth, and the archaeological sequences through which warfare seems to emerge in different parts of the world.
Is war an ancient adaptation—or a more recent cultural development? And is the answer relevant to our modern quest for a more peaceful world?
Enjoy!

FACT-CHECKING
No errors have been detected in this conversation. If you notice one, please get in touch via Substack or the form below.

LINKS
Fry's 2026 book: ⁠Advanced Introduction to Conflict Resolution⁠
Support: ⁠⁠Patreon.com/OnHumans⁠⁠
Articles & newsletter: ⁠⁠OnHumans.Substack.com⁠⁠
Get in touch: ⁠⁠https://forms.gle/h5wcmefuwvD6asos8⁠⁠
Music credit: Aleksey Chistilin (Lexin_Music) via Pixabay.

NAMES MENTIONED
Douglas P. Fry | Luke Glowacki | Richard Wrangham | Brian Ferguson | Christopher Boehm | Richard B. Lee | Donald E. Brown

ETHNIC GROUPS AND HISTORICAL REGIONS
Northwestern Alaska | Valley of Oaxaca | Jebel Sahaba  | Monte Albán | Zapotec Empire | Calusa people | Batek people | Orang Asli | Juǀ’hoansi, !Kung | Mbuti 

KEY WORDS
Origins of war | prehistory of war | history of warfare | causes of war | why humans go to war | anthropology of war | anthropology of peace | peace studies | conflict studies | war studies | peace and conflict studies | evolutionary anthropology | human evolution | human nature and war | hunter-gatherer warfare | hunter-gatherers | nomadic hunter-gatherers | mobile foragers | complex hunter-gatherers | prehistoric violence | interpersonal violence | coalitionary aggression | coalitionary killing | lethal aggression | human aggression | conflict resolution | restraint of aggression | archaeological evidence of war | archaeology of warfare | archaeological record | Pleistocene | Holocene | Neolithic warfare | origins of social complexity | sedentism | permanent settlements | food storage | population growth | population density | resource competition | resource intensification | marine resources | aquatic resources | Neolithic revolution | human universals | evolutionary psychology | chimpanzee warfare

History is full of wars. Why? Is war driven by fear? Greed? Revenge? Ambitious leaders? Is it rooted deep in human nature—or does it emerge only under particular social conditions?
And what do we learn if we change the angle from wars to non-wars? What lessons emerge from a study of all the periods and regions where war did not take place? 
My guest in this two-part mini-series is Douglas P. Fry, an anthropologist who has spent decades studying these questions. He is also a returning guest, and one of the first scholars ever to appear on this podcast.
In Part II of our conversation, we will return to the topic of our episode from years back: the origins of war in prehistory. In this first part, however, we take a very different approach. We discuss lessons from modernity, with our topics ranging from the quest for peace after WWII to the societies in the Brazilian Amazon and Indigenous North America.
What makes former enemies trust one another? What roles are played by equality, trade, or a new shared enemy? And how can cycles of fear, retaliation, and revenge be reversed without simply surrendering to aggression?
At a time when war once again dominates the news, these questions could hardly be more urgent. But they also point towards a part of the human story that is too easily forgotten: our capacity not only to make war, but to understand it—and to build peace that lasts.
Enjoy!

FACT-CHECKING
My wording on Ukraine giving up its nuclear arsenal in exchange for "security guarantees" is slightly stronger than the formal language of the Budapest Memorandum, which talked of “security assurances” rather than legally binding security guarantees.
If you notice a factual error in this conversation, please get in touch via Substack or the form below.

LINKS
Fry's 2026 book: Advanced Introduction to Conflict Resolution
Support: ⁠Patreon.com/OnHumans⁠
Articles & newsletter: ⁠OnHumans.Substack.com⁠
Get in touch: ⁠https://forms.gle/h5wcmefuwvD6asos8⁠
Music credit: Aleksey Chistilin (Lexin_Music) via Pixabay.

NAMES MENTIONED
Douglas P. Fry | Geneviève Souillac | Jean Monnet | Konrad Adenauer | Mahatma Gandhi | Edward Westermarck | Charles E. Osgood | Brian Ferguson | Eleanor Roosevelt | Vladimir Putin 

KEY WORDS
Douglas P. Fry | peace studies | conflict studies | war studies | peace and conflict studies | anthropology of war | anthropology of peace | war and peace | causes of war | origins of war | human nature and war | peacebuilding | conflict resolution | peace systems | lasting peace | international cooperation | nonviolence | revenge | reciprocity | negative reciprocity | deterrence | security dilemma | arms race | nuclear weapons | nuclear disarmament | Treaty on the Prohibition of Nuclear Weapons | TPNW | Budapest Memorandum | United Nations | UN peacekeeping | Blue Helmets | UN Security Council | international law | global governance | World War II | Second World War | post-war peace | European integration | Jean Monnet | European Coal and Steel Community | Switzerland | Nordic peace | Åland Islands dispute | League of Nations | Upper Xingu peace system | Indigenous peace systems | Haudenosaunee Confederacy | Iroquois Confederacy | Great League of Peace | GRIT strategy | Graduated Reciprocation in Tension Reduction | Charles E. Osgood | Edward Westermarck | Ukraine war | Russia–Ukraine war

Was India once an affluent empire, later impoverished by British colonisation? Or was India never rich to begin with?
More generally, what does historical data on wages and other economic indicators tell us about the broader story of the making of the modern world – a world with great affluence, but where much of the riches are still concentrated in the Western world.
For over 20 years now, Stephen Broadberry and Bishnupriya Gupta have worked to measure the evolution of global living standards from the medieval period onwards.
In this episode, they begin by discussing a comparison between the historical economies of India and Britain. We then continue to a broader story of the living standards of the pre-industrial world. We also discuss different theories of the “Great Divergence” between the West and the rest of the world. We finish by turning our attention to the future, asking if the 21st century will be remembered as the Asian century.
This episode concludes the five-part series on the making of the modern world, produced by CAGE Research Centre and On Humans. 
LINKS AND REFERENCES
Do you prefer reading to listening? You can find⁠ a summarised essay ⁠of this conversation, with a bibliography, at our series page:⁠ ⁠https://warwick.ac.uk/fac/soc/economics/research/centres/cage/news/podcasts/⁠⁠
 NAMES MENTIONED
Kenneth Pomeranz | Angus Maddison | Daron Acemoglu | James Robinson |  Nico Voigtländer | Hans-Joachim Voth | Debin Ma | Robert Allen | Joel Mokyr
 
KEYWORDS
Economics | History | Global Economic History | Industrial Revolution | Indian history | Imperial history | East India Company | Emperor Akbar | Colonisation | Historical GDP estimates | Historical living standard estimates | Wage history | History of labour | Social history | Comparative development | State capacity | Malthusian trap | History of Technology 
INFO
Guests: Bishnupriya Gupta (University of Warwick) and Stephen Broadberry (University of Oxford)   ⁠⁠⁠
Contact: ⁠greatdivergencepod@gmail.com