On Humans

Over half a century, Sarah Blaffer Hrdy has challenged many of our myths about parenting, attachment, and "human nature".

In this conversation, we dive into her remarkable career, culminating in her new book, Father Time.

[You can now order Father Time via Amazon or Princeton Uni Press]

We discuss a variety of topics, from hunter-gatherer parenting to the limitations of comparing humans to chimpanzees. We also discuss "allomothers", attachment theory, and the tragedy of infanticide. We finish with a discussion on the remarkable social changes in fatherhood and the neuroscience that has enabled it.

As always, we finish with Hrdy’s reflections on humanity.

Timestamps

(04:15) Myths

(10:10) Attachment Theory 

(20:50) Hunter-Gatherers

(24:30) Modern Parenting 

(26:00) Infanticide 

(34:00) Monkey parenting (in South America)

(36:10) Why we share 

(40:00) Husbands, grannies, or aunties?

(43:10) Father Brains

ANNOUNCEMENT

I'm writing a book! It is about the history of humans, for readers of all ages. Do you want access to early drafts? Become a member on Patreon.com/OnHumans⁠⁠⁠⁠⁠

LINKS

Want to support the show? Checkout ⁠⁠⁠⁠Patreon.com/OnHumans⁠⁠⁠⁠

Want to read and not just listen? Get the newsletter on ⁠⁠⁠⁠OnHumans.Substack.com⁠⁠⁠⁠

MENTIONS

Terms: allomothers, mobile hunter-gatherers (i.e. immediate return foragers), matrilineal and patrilineal kin

Names: Edward O. Wilson, Robert Trivers, John Bowlby, John Watson, Charles Darwin, Mary Ainsworth, Melvin Konner, Barry Hewlett, Nikhil Chaudhary (#34), Nancy Howell, Martin Daly, Margot Wilson, Amanda Reese, Judith Burkart, Carl Von Schaik, Alessandra Cassar, Ivan Jablonka, Kristen Hawkes (#6), Ruth Feldman (#3), Richard Lee

Modern cities are unique. Never before have so many people lived so close to each other. But just how unique is our modern cosmopolitanism?

Completely unique, says a traditional theory.

Humans evolved in tiny groups. These groups were not only smaller than modern cities. They were smaller than medieval towns. Indeed, hunter-gatherers often move in bands of 25 people or so. These bands might draw people from a "meta-group" of 150 people — but not more. And so, 150 people is the "maxiimum" group size natural for humans. Or so the theory goes.

My guest today thinks that this is wrong. 

Cecilia Padilla-Iglesias is an evolutionary ecologist who studies hunter-gatherer societies. And her work points to a very different conclusion. Yes, hunter-gatherers spend much of their time in small bands. But these bands can form much larger groups of connections, extending further and further away, even to areas with different languages. Even in the rainforest, cosmopolitanism is the norm.

So what do hunter-gatherer societies look like? And are they really good models of our deep past? We discuss these and other topics in this episode, touching upon topics such as:

(04:00) Living with hunter-gatherers

(10:30) Fluid societies

(14:20) Dunbar’s mistake 

(17:20) Dawkins’ mistake

(21:20) Ancient DNA of hunter-gatherers

(23:20) What made H. Sapiens special?  

(25:40) Mobility, diversity, and technology

(28:20) Sympathy and xenophobia

(34:00) Ancient DNA (again)

(41:30) Jungle cosmopolitanism

(43:40) Was agriculture a mistake?

As always, we end with my guest's reflections on humanity.

LINKS

Want to support the show? Checkout ⁠⁠⁠Patreon.com/OnHumans⁠⁠⁠

Want to read and not just listen? Get the newsletter on ⁠⁠⁠OnHumans.Substack.com⁠⁠⁠

MENTIONS

Names: Richard Dawkins, Kim Hill, David Reich, Andrea Migliano

Books: God Delusion (Dawkins), Who We Are And How We Got Here (Reich), The Human Swarm (Moffett)

Ethnic groups: Bayaka (Congo), Hadza (Tanzania), Ache (Paraguay), Agta (Philippines)

Articles: For links to articles, see OnHumans.Substack.com/p/Links-for-Episode-39-Hunter-Gatherer

Infinity is a puzzling idea. Even young children ponder its various manifestations: What is the biggest number? Does the universe have an edge? Does time have a beginning?

Philosophers have tried to answer these questions since time immemorial. More recently, they have been joined by scientists and mathematicians.

So what have we learned? Can we finally understand infinity? And what has this quest taught us about ourselves? 

To explore this topic, I am joined by philosopher Adrian W. Moore. 

Professor Moore is a special guest for two reasons. First, he is a world expert on infinity, known for an excellent BBC series, "History of the Infinite". More personally, he is the head tutor of Philosophy at St Hugh’s College, Oxford, where I studied my BA in Philosophy and Psychology. It has now been ten years since Prof Moore interviewed me and, for whatever reason, accepted me as a student. I feel honoured to mark the occasion with this episode.

In this episode, we discuss:

(02:35) Why infinity fascinates

(12:20) Greeks on infinity

(20:05) A finite cosmos? 

(25:00) Zeno’s paradoxes

(32:35) Answering Zeno

(42:35) Measuring infinities? Georg Cantor

(54:05) Infinity vs human understanding

(66:20) Mystics on infinity

As always, we finish with Prof Moore’s reflections on humanity.

LINKS

Want to support the show? Checkout ⁠⁠Patreon.com/OnHumans⁠⁠

Want to read and not just listen? Get the newsletter on ⁠⁠OnHumans.Substack.com⁠⁠

MENTIONS

Names: Aristotle; Zeno; Archytus; Ludwig Wittgenstein; Kurt Gödel; Alan Turing; Georg Cantor; William Blake; Immanuel Kant 

Terms: Pythagoreans; Zeno’s paradoxes; calculus; transfinite arithmetic; counting numbers, i.e. positive integers; absolute infinities, or inconsistent totalities

Books: The Infinite (Moore)

Other scholarship: For games on infinite boards, see e.g. the work of Davide Leonessi: https://leonessi.org/

Why are we furless? Why do we cook our food and use spoken language? And how does climate change, sashimi, or the banks of Central America relate to human origins? 

Human evolution is a deeply puzzling topic. But behind this dense mist lies many keys to our self-understanding. To guide us through the foggy territory, I am joined by Dr Ian Tattersall, a curator emeritus at the American Museum of Natural History (New York).

In this episode, Dr Tattersall and I discuss:

(04.00) An ancient climate change

(07:20) First humans

(11:20) Fire

(17:50) Fish

(21:40) Rocks

(24:00) Evolution vs Innovation

(25:30) Brain growth

(36:10) Children

(39:50) Language

(48:20) Why?

As always, we finish with Dr Tattersall's reflections on humanity.

LINKS

Want to support the show? Checkout ⁠Patreon.com/OnHumans⁠

Want to read and not just listen? Get the newsletter on ⁠OnHumans.Substack.com⁠

MENTIONS

Names: Richard Wrangham (see ep. 21), Susan Schaller, Ildefonso, Jane Goodall, Sarah Blaffer Hrdy, Yuval Noah Harari 

Books: Masters of the Planet (Tattersall), Man Without Words (Schaller), Sapiens (Harari)

Technical terms: Oldowan tool culture (first stone tools, c. 2.5 million years ago), Acheulean hand axe (first major update in stone tools, c. 1.6 million years ago)

Fossils: Lucy (3.2 million years old); Turkana Boy (aka. Nariokotome Boy, 1.6 million years old)

Hominin species: Australopithecines, Homo ergaster, Homo erectus, Homo heidelbergensis, Homo neanderthalensis, Homo sapiens

A note on hominin taxonomy: Homo habilis was traditionally considered the first human and the first maker of stone tools. Dr Tattersall is among the many critics of this old idea. According to him and many others, there is no separate tool-making species called Homo habilis. Rather, Australopithecines started making stone tools without any change in the biology of the species. Also, it is worth noting that Dr Tattersall rejects the traditional view which gives a big role for Homo erectus in the human story. In this traditional view, Turkana Boy’s species, Homo ergaster, is called an African Homo erectus. Dr Tattersall and many others argue that this is a historic hangover with little basis in the biological evidence.

We are conscious creatures. But why? Why did consciousness evolve? Can we use biology to explain the origins of feeling and meaning? Or will consciousness forever escape the grip of the scientific method? 

Eva Jablonka has thought hard about these issues. An eminent evolutionary biologist, she became famous for her pioneering work on epigenetic inheritance. More recently, she has produced very original work on the evolution of consciousness with her colleague, neuroscientist Simona Ginsburg. So invited him on the show to discuss the evolution of consciousness, or what she beautifully calls "the sensitive soul".

In this episode, we discuss themes such as:

(03:00) What is consciousness? 

(10:45) Four links between evolution and consciousness

(27:30) Are robots conscious? Consciousness and vulnerability

(30:45) Which animals are conscious? Consciousness and the Cambrian Explosion.

(34:30) Can science fully explain consciousness?

(48:00) The future of consciousness

As always, we end with Jablonka’s reflections on humanity.

LINKS

Want to support the show? Checkout Patreon.com/OnHumans

Want to read and not just listen? Get the newsletter on OnHumans.Substack.com

MENTIONS

Books: Evolution of the Sensitive Soul, Picturing the Mind (both my Eva Jablonka & Simona Ginsburg)

Terms: Sensitive soul, phenomenal consciousness, intentionality (i.e. "aboutness"), the Cambrian explosion, cephalopods, anthropods, vertebrates

Names: Aristotle, Simona Ginsburg, Jonathan Birch, Antonio Damasio

Why do we love? What brings us together? How to heal ethnic hatred?

According to my guest, the answer to all these questions lies in the human desire to grow ourselves through connecting with others.

Arthur Aron is a psychologist who studies human bonding in all its forms. A pioneer in the field, he has studied topics from connecting with strangers to maintaining romance in life-long marriages. And many of his findings are ultimately hopeful.

In this conversation, we discuss topics such as:

(4:30) Why we love 

(12:50) Tools to cultivate love

(24:30) Friendships with the ethnic "other” 

(31:30) Are we naturally xenophobic?

MENTIONS

Names: Elaine Aron, Helen Fisher, Stephen Wright

Articles: For links to videos, articles, and the 36 Questions, see https://onhumans.substack.com/p/links-for-episode-35

MORE LINKS

Read the On Humans newsletter at OnHumans.Substack.com

Support On Humans at Patreon.com/OnHumans

Can evolution shed light on our mental health?

Nikhil Chaudhary thinks so. He is an anthropologist at the University of Cambridge who specialises in the links between evolution and psychiatry. In this clip, Dr Chaudhary explores the evolutionary origins of ADHD, depression, and anxiety.

For our longer conversation on parenting and family life, see episode 34 of the On Humans Podcast.

We expect a lot from parents, especially from mothers. “Maternal instincts” are such, we are told, that mothers should gain almost literal superpowers from the joy of parenting. 

Unfortunately, many parents face a different reality. Having children can be one of the most stressful times of life, amplified by feelings of guilt and inadequacy. 

Why is this? Is this an inevitable part of the human condition? Or is the fault in our modern society? And how would we know the answer? 

To address these questions, anthropologists have started comparing family lives in industrial societies with those of the last remaining hunter-gatherers. 

Nikhil Chaudhary is one such anthropologist. A researcher at the University of Cambridge, he recently co-authored a remarkable paper on what we have learned about the family lives of hunter-gatherers. I invited him on the show to discuss the findings and their implications.

So what is family life like amongst hunter-gatherers? Chaudhary's research paints a fascinating picture. Indeed, industrial societies can learn a lot from them. But not everything is easy for them, either.

In addition to parenting, our conversation touched upon themes from monogamy and polyamory to parental grief, health spending, and the stark contrast between human and chimpanzee mothers.

MORE RESOURCES

If you enjoy our conversation and want to learn more about hunter-gatherer studies, see episode 14 with Vivek Venkataraman. For more information on the anthropology of monogamy and beyond, see episode 11 with Helen Fisher. 

For written content on this and other conversations, subscribe to the newsletter at OnHumans.Substack.com. 

MENTIONS

Names: Sarah Blaffer Hrdy (see upcoming episode this spring), Richard Wrangham (see episode 21), Alan Watts 

Terms: Partible paternity, alloparenting, post-partum depression, the continuum concept, NHS (UK’s National Health Services), human self-domestication (see episode 21)

Ethnic groups: BaYaka (both the Mbendjele in Congo and the Aka in CAR), Ache (in Paraguay), Hadza (in Tanzania), Agta (in the Philippines), Bantu peoples (the major ethnolinguistic group in most southern African countries)

Articles: For links to articles mentioned in this conversation, see https://onhumans.substack.com/p/links-for-episode-34

SUPPORT

You can support the On Humans podcast by becoming a member at Patreon.com/OnHumans

Happy New Year 2024!

To celebrate the new year, Spotify sent me a bunch of data points about 2023. I was particularly interested in one question: which conversation moved people the most? I already knew which episode people played the most. (That's episode 17 with Bernardo Kastrup.) But to listen is one thing. To share with friends and family is another.

The most shared episode was my conversation with Helen Fisher, titled "A Cultural Biology of Sex, Love, and Monogamy". It was one of my favourite conversations, too. Fisher offered a sweeping take on romantic love, combining fascinating anthropology with practical tips about maintaining passion in relationships. She even convinced my parents to re-design their TV arrangement...

Perhaps it deserves one more share. So here you go!

___

ORIGINAL SHOW NOTES

Why do we love? And how much does our culture shape the way we do so?

In this episode, Ilari talks with Helen Fisher about the powers that drive and shape our romantic relationships. Ilari and Professor Fisher discuss:

• Is romantic love a modern invention?
• Is monogamy a social invention? 
• Do men care more about sex? Do women care more about romance?
• Why agriculture, especially with the plough, caused havoc in romantic relationships.
• Why divorces might be on the decline.
• A science-based guide for maintaining romantic relations (based on couples who are still in love after 25 years)
• Why (certain) antidepressants can kill the sex drive and blunt romantic love (to read more, see the end of the notes)
• How common is polygamy or polyandry? Where in the world do we find most "free love"?
• Why did homosexuality evolve?

Names mentioned

• Irenäus Eibl-Eibesfeldt (as recounted by Alison Gopnik in her The Gardener and the Carpenter)
• Bill Jankowiak
• Robert Sternberg (see episode 7)
• Anderson Thompson
• Bertrand Russell 

Technical terms and ethnic groups mentioned

• Ventral tegmental area VTA
• Hypothalamus
• Dopamine, testosterone, oxytocin, vasopressin, serotonine
• Monogamy (serial or lifelong; social or biological)
• Polygamy (several wives) and polyandry (several husbands) 
• Tlingit (the polyandrous Inuit society with wealthy women)
• Oneida community (in New York State)

Dig Deeper

Antidepressants: To read more about the possible effects of SSRIs on sex drive and romantic love, see ⁠Tocco and Brumbaugh (2019)⁠. Remember that this is for information only, and is not health advice. Always discuss with your doctor before making decisions about your medication.

Polyamory: In the episode, Professor Fisher suggests that many Amazonian tribes have informal polyandry, i.e. women have many partners, albeit only one formal husband. However, there are ⁠non-academic sources⁠ suggesting that formalised polyandry is common in the Zo’é community in Amazon. For some of these photos of Zo’é and other Amazonian tribes, many of whom exhibit remarkably liberal attitudes to sex, see the ⁠recent Amazonia exhibition⁠ in the London Science Museum.

This is the final episode of 2023. And it is a very odd episode.

My guest is Gregory Forth. He is an anthropologist who specializes in the biological theories of indigenous peoples.

Forth was doing this work on the Flores Island, Indonesia, during the 2003 discovery of a new hominin species: Homo floresiensis. This was an exciting discovery for many. But Forth was, in his own words, "gobsmacked".

In his own studies, Forth had been puzzling over a species the local people called lai ho'a, a creature that was not quite human and not quite monkey. It was something in between. According to the local people, the lai ho'a live deep in the local rainforest. They are difficult to see. But people do see one occasionally. They are about a meter in height, just as Homo floresiensis. And they walk on two legs – a feature that separates humans from other mammals.

So what should we make of all of this? Could Homo floresiensis, or its descendants, still be alive? Or is this just another fantasy in the realm of cryptozoology? And what would it be like to encounter a species that is half human, half ape? What rights would they get? How would it challenge our ideas about "humanity"?

This is my attempt at making sense of this peculiar case. I hope you enjoy it!

READ MORE

To read the full story in detail, I highly recommend Forth’s thoughtful and non-sensetationalist book, ⁠Between an Ape and Human: An Anthropologist on the Trail of a Hidden Hominoid.

I am now publishing episode breakdowns, essays, and much more. Read online or sign up for the newsletter on ⁠OnHumans.Substack.com⁠! 

SUPPORT

Please consider supporting the show on Patreon.com/OnHumans.

MENTIONS

Ethnic groups: Lio People (on Flores), Southeast Asian “Pygmies” (i.e. indigenous people with very short stature)

Hominin species: Homo floresiensis, Austrolopithecine, Homo erectus, Homo neanderthalensis, Homo denisovans, Homo sapiens