A Lock of Hair Could Rewrite Knowledge Of The Inca Empire

Summary

Short Wave — "A Lock of Hair Could Rewrite Knowledge Of The Inca Empire"

Host: Regina Barber (NPR)
Reporter: Nell Greenfieldboyce
Guests: Kit Lee (University of St. Andrews), Sabina Hyland (University of St. Andrews), Manny Medrano (Harvard University)
Air Date: August 27, 2025
Episode Length: ~13 minutes (excluding ads)

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Episode Overview

This Short Wave episode dives into how a single khipu (an ancient knotted cord) made with human hair uncovered at the University of St. Andrews might upend traditional ideas about who created written records in the Inca Empire. The story melds archaeology, chemistry, and anthropology to reveal that literacy and khipu-making in the empire may have been more widespread—and more ordinary—than historians once believed.

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Main Themes & Purpose

• Rethinking Inca record-keeping: Challenging the idea that only elite, male record-keepers created and could read khipus.
• Scientific detective work: How new analyses, such as hair chemistry, provide insight into the status and lives of ancient record-keepers.
• Continuity of tradition: Exploring connections between ancient and modern khipu practices in Andean communities.

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Key Discussion Points & Insights

1. What is a Khipu?

[04:20–05:34]

• Khipus are intricate record-keeping devices comprising one main cord, from which pendant cords hang; knots and colors encode information.
• The system is "a kind of code … the type of knot, the numbers of cords, the order, their color, everything has meaning" (Nell Greenfieldboyce, 02:09).

2. The Rarity and Survival of Khipus

[05:34–06:01]

• Few ancient Inca khipus survive (~1,000), due to deterioration and destruction by Spanish colonizers.
• Many surviving khipus' original contexts and provenances are unknown, complicating interpretation.

3. Reading Ancient and Modern Khipus

[06:07–07:11]

• Ancient khipus’ meanings remain largely undeciphered.
• In modern Andean communities, khipus are sometimes still made for agricultural or funerary purposes.
• "During COVID you had a resurgence of funerary khipus, which are more of a cultural religious signifier as well" (Kit Lee, 06:47).
• Modern khipus have been considered less 'authentic', thought disconnected from ancient practice.

4. Who Made the Khipus? The Social Status Question

[07:18–08:02]

• Academic consensus has long held that only high-status, elite men produced khipus in the Inca bureaucracy; Spanish accounts reinforce this.
• Modern khipus tend to be made "by lower status people. So hacienda workers, peasant laborers, herders" (Kit Lee, 07:18).

5. A Curious Khipu—Made from Human Hair

[07:45–09:03]

• Sabina Hyland and Kit Lee at St. Andrews examine a khipu thought to be modern—until carbon dating reveals it’s about 500 years old.
• Surprise: The main cord is made of human hair.
  • "Sabina, this primary cord is human hair." (Kit Lee, 08:02)
  • "A person cut off a hank of their hair and then they doubled it over and twisted it." (Sabina Hyland, 08:40)
• Historic precedent: Human hair was sometimes used as a signature, signifying the khipu’s maker.

6. Unlocking Social Class with Chemistry

[09:03–09:52]

• Chemical analysis (carbon, nitrogen isotopes) of the hair reveals a “commoner’s diet”—little meat, no maize beer (a staple of elites).
  • "This person who appears to have made this khipu had the diet of a commoner." (Sabina Hyland, 09:46)
• Maize beer was culturally and ritually mandatory for elite khipu officials.
  • "These very high ranking elite khipu officials, as part of … record keeping, they were involved in rituals in which it was mandatory to drink a lot of maize beer." (Sabina Hyland, 10:08)

7. Rethinking the Mythology of Inca Khipus

[10:29–11:19]

• If a commoner made this ancient, sophisticated khipu, then literacy and participation in record-keeping were likely more widespread.
• The episode challenges "the glorious past of the Andes, that it's a bygone day … because the Spanish destroyed it, colonialism destroyed it." (Kit Lee, 11:00)
• The old view: all post-colonial khipus are “almost like a triviality” (Sabina Hyland, 11:19).

8. Modern Connections: Community and Continuity

[11:33–12:12]

• Community in Jacul, a remote Andean village, still maintains ancestral khipus, some with human hair “signatures.”
  • "They asked me to look at it. They'd never shown their khipus to outsiders before." (Sabina Hyland, 11:43)
• Tassels remain a feature in both ancient and modern khipus, suggesting deeper cultural continuity.
  • Hyland hopes to document their significance through continued ethnography: "It's not like using AI. It's just talking with people." (Nell Greenfieldboyce, 12:16)

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Notable Quotes & Memorable Moments

• "There's this idea of [the Inca empire] being a glorious past of the Andes, that it's a bygone day … because the Spanish destroyed it, colonialism destroyed it."
  — Kit Lee, [11:00]
• "This person who appears to have made this khipu had the diet of a commoner."
  — Sabina Hyland, [09:46]
• "Maize beer is different, because these very high ranking elite khipu officials, as part of the process of getting record keeping, they were involved in rituals in which it was mandatory to drink a lot of maize beer."
  — Sabina Hyland, [10:08]
• "I know, talking to people, it's a radical notion, very old school."
  — Regina Barber, [12:12]

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Timestamps of Important Segments

• 00:18–01:26: Introduction to the Inca empire & unique aspects of their record keeping
• 04:20–04:39: What khipus look like; visualization for listeners
• 05:16–05:46: Challenges in deciphering ancient khipus
• 06:07–06:47: Khipus in modern Andean customs
• 07:18–07:26: Who made ancient vs. modern khipus, class distinctions
• 08:02–08:40: Discovery: khipu made of human hair, personal signatures
• 09:40–09:52: Diet analysis suggests record keeper was a commoner
• 10:29–11:19: Re-examining myths: khipus as an elite or a communal practice
• 11:43–12:12: Continuity of tradition in Jacul, modern Andean khipus

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Episode Tone and Style

The conversation—anchored by curiosity, warmth, and gentle humor—conveys the thrill of scientific discovery and historical detective work. The guests and hosts are open about surprises in their research, eager to challenge assumptions, and deeply respectful of the Andean communities keeping tradition alive.

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In Summary

This episode of Short Wave brings fresh evidence to light, using a strand of human hair to rethink the history of the Inca empire. It suggests that the power to record, organize, and transmit knowledge wasn’t confined to the elite—and that living Andean traditions are not just a shadow of a lost past, but part of an ongoing and evolving story.

Listeners leave with new questions: Who really gets to "write" history? And whose threads, knotted quietly centuries ago, might yet reshape what we think we know?

Transcript

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[Regina Barber]

You're listening to Short Wave from npr. Hey, shortwavers. Regina Barber here. And today on the show, we are diving into an unusual part of life in the Inca empire. In the 15th and 16th centuries, this empire ruled over 10 million people in South America, covering modern day Peru, Ecuador, Bolivia, northwest Argentina. At the time, it was the largest empire in the world.

[Nell Greenfieldboyce]

So as you can imagine, it had things like an extensive network of roads, impressive architecture. It had a whole bureaucratic system to keep track of everything that was going on.

[Regina Barber]

That that's NPR science correspondent Nell Greenfield. Boyce. Hey, Nell.

[Nell Greenfieldboyce]

Hey, there.

[Regina Barber]

So there is a way that the Inca empire is unique.

[Nell Greenfieldboyce]

Well, maybe there's lots of ways. But we are going to talk about.

[Regina Barber]

One thing, this intersection of numbers and knots, something I actually learned about last year. On top of that, like, famous Inca fortress, Machu Picchu.

[Nell Greenfieldboyce]

I am so jealous. You have been there. I have not. I learned about these knots and numbers when I was talking to a researcher named Kit Lee. She's affiliated with the University of St. Andrews in Scotland.

[Kit Lee]

When you're learning about empires in school, oftentimes the way they teach them is that every empire, big civilization, has writing. So the Inca empire is almost always called out as an exception to this. Oh, there's such a big empire that covered half the continent, but they don't have writing? How could that be?

[Nell Greenfieldboyce]

She says what's often overlooked is that they did have this elaborate system of record keeping, you know, all kinds of records that involved making knots in cords.

[Regina Barber]

Yeah, knots in these cords. It's amazing to think that this huge empire kept all these records. And I remember seeing this recreation of one and there were like colors in the cords. They were really, really beautiful. And those colors were important, too, right?

[Nell Greenfieldboyce]

Yeah. I mean, the colors contained meaning. The position of the knots along the cord, the type of knot, the numbers of chords. Like everything was a kind of code. And literacy in this form of writing or record keeping was assumed to be this kind of rare, esoteric thing that only the highest levels of Inca society could do. You know, kind of this elite practice by men in the ruling class. But you know, what Kit and a colleague recently told me is that they came across this one set of really unusual knotted strings that has called all of that into question.

[Regina Barber]

Ooh, I love where this is Going today on the show why anthropologists may have been wrong about which members of the Inca empire made these ancient records and what that means for understanding how these knots are related to objects that some people still make today. You're listening to Shortwave, the science podcast from npr.

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[Regina Barber]

Okay, now let's just help people visualize what these Inca knot records look like. I'm sitting here, I'm looking at this picture you sent me from the Smithsonian, and we've got this like long cord, sort of horizontal in the photo. And then hanging down vertically from that horizontal cord are these other cords with knots in them.

[Nell Greenfieldboyce]

Yeah, so there's the so called main chord, the horizontal one, and then the ones hanging down from it are called pendant cords. And the whole thing, the whole record is called a khipu. The word comes from part of the Inca language that means knot. And everything has meaning in this thing. The placement of the knots along the strings, the order of the strings, their color, everything is thought to be kind of a record, something that somebody could look at and make and read to look at, you know, a census or crop records or whatever they wanted to be counting and keeping track of.

[Regina Barber]

And what we're looking at right now is like half a millennia old. Like, can people still read this today?

[Nell Greenfieldboyce]

It's hard. I mean, some Khipos are thought to contain numerical information so they can sort of tell that the knots are arranged in a decimal system with like a place for tens, a place for hundreds. I mean, there's lots of things you would want to count like that.

[Manny Medrano]

Right.

[Regina Barber]

That makes a lot of sense, that decimal system to me.

[Nell Greenfieldboyce]

But the thing is, there aren't really a lot of khipus still in existence from the Inca empire. I mean, they were made of cotton, so a lot just kind of degraded in the environment.

[Manny Medrano]

Yeah.

[Nell Greenfieldboyce]

And then the Spanish colonizers actually destroyed and burned a lot of them.

[Sabina Hyland]

Oh geez.

[Nell Greenfieldboyce]

So in museums and universities worldwide, there's only about a thousand quipus still in existence and there's often no information about where they originally came from.

[Regina Barber]

Yeah, I can see how that would make it very hard to like learn more about them, to be able to read these records.

[Nell Greenfieldboyce]

I was talking to Harvard University khipu researcher Manny Medrano and I asked him, like, to what extent can people today read Khipus?

[Manny Medrano]

Well, it depends which khipus we're talking about. Right. Because of an Inca khipu that came out of a grave, for example, you know, from the 1400s. I'm not aware of any modern reading, let's call it of an object of that age that is universally agreed upon.

[Nell Greenfieldboyce]

But then you've got khipus that have been made by communities in the Andes in more recent times. You know, there is this tradition of kind of symbolic nodding.

[Regina Barber]

So you could just ask them. Right.

[Nell Greenfieldboyce]

And researchers do. I mean, Kit Lee told me, you know, some are related to agriculture, like keeping track of herds, but you also.

[Kit Lee]

Have, during COVID you had a resurgence of funerary khipus, which are more of a cultural religious signifier as well.

[Nell Greenfieldboyce]

So.

[Kit Lee]

So both of them are happening like.

[Nell Greenfieldboyce]

People are buried with a sort of long khipu string tied around their waist. But Lee told me it's been thought that these modern practices weren't really related to the more ancient khipu records from the Inca empire.

[Manny Medrano]

Yeah.

[Regina Barber]

Why do they assume that?

[Nell Greenfieldboyce]

Well, for one thing, the modern khipus just look different, like they have a different shape. And then there's the people who make them.

[Kit Lee]

And modern khipus tend to be made by lower status people. So hacienda workers, peasant laborers, herders.

[Nell Greenfieldboyce]

And like I said before, you know, records from the colonizers said that khipus in the Inca empire were made by elite men. So you know, this high level bureaucracy at the top levels of the ruling class of this empire.

[Manny Medrano]

Yeah.

[Regina Barber]

And you said that this may be called into doubt with like this one set of knotted strings, Right?

[Nell Greenfieldboyce]

Exactly. So it's a khipu acquired by the University of St. Andrews and. And Sabina Hyland works there. She told Me she initially thought this thing was a modern khipu, but then she did scientific dating and it showed that this khipu was about 500 years.

[Sabina Hyland]

Old, which astonished me. That was the first surprise. Then Kit, I was showing it to Kit and this was the second surprise. Kit looked at me and said, sabina, this primary cord is human hair.

[Regina Barber]

I love her enthusiasm, but like human hair? How is that the key here?

[Nell Greenfieldboyce]

Well, you know, they had thought like, okay, maybe it's animal hair. But when Kit was looking at it, she's like, no, it's too long and glossy to be, you know, animal hair, like from a llama or something. I mean, this is a long dark brown cord made of long human hair. It's like three feet long. So it's like years of hair growth.

[Sabina Hyland]

What it is is a person cut off a hank of their hair and then they doubled it over and twisted it.

[Nell Greenfieldboyce]

The reason this is important is that she knew of some historical information suggesting that herders and others would sometimes tie human hair to a khipu as a kind of signature.

[Manny Medrano]

Right. Okay.

[Nell Greenfieldboyce]

So she thought maybe this hair came from the person who made this khipu.

[Regina Barber]

But. But there's no way to know for sure that it was the person who made it.

[Nell Greenfieldboyce]

No, you don't know for sure. But she knew that in the Inca Empire, hair had a lot of meaning as a sort of personal signifier. Like the emperor hair clippings were saved during his lifetime and worshiped just as he was, you know.

[Manny Medrano]

Okay.

[Nell Greenfieldboyce]

And so she thought, here I have this hair that could be from the maker of this khipu. And she realized she could do a chemical analysis of the elements like carbon and nitrogen in this hair to get clues about what kind of food this person ate. This is a kind of analysis that's been done a lot in the past on like, things like mummies.

[Regina Barber]

This is so fascinating. I love it. What did she find?

[Nell Greenfieldboyce]

Well, she says it didn't look like a rich person's diet. Wow.

[Sabina Hyland]

This person who, who appears to have made this khipu had the diet of a commoner.

[Nell Greenfieldboyce]

So not a lot of meat and not beer made from maize, which was the popular ritual drink of the ruling class.

[Manny Medrano]

Okay.

[Nell Greenfieldboyce]

And I asked her, I was like, look, maybe this person was just a vegetarian, you know? And she was like, sure, you could theoretically avoid meat, but maize beer is.

[Sabina Hyland]

Different because these very high ranking elite Khipu officials, as part of the process of getting record keeping, they were involved in rituals in which it was mandatory to drink a lot of maize Beer.

[Nell Greenfieldboyce]

She just doesn't think that was avoidable if you were in the ruling class.

[Regina Barber]

So then this means that this person must have not been, right, an exalted person. They might have been a commoner. Right?

[Nell Greenfieldboyce]

I mean, that's the idea. And if that's true, then maybe the Spanish colonizers got it wrong when they wrote these accounts of what they thought was going on in the Inca empire. Very possible. Maybe literacy in khipu making and reading was more widespread. And Kit Lee told me that, you know, the Inca empire and the Khipus have really been mythologized to a certain extent. There's this idea of it being a.

[Kit Lee]

Glorious past of the Andes, that it's a bygone day, you know, because the Spanish destroyed it, colonialism destroyed it.

[Nell Greenfieldboyce]

And, you know, if it was destroyed, then there's this assumption that, of course, these not records that people make today are just this kind of, like, degraded form of what used to be this, like, glorious past. Sabina Hyland told me, everyone knew, right?

[Sabina Hyland]

The khipus were only made by high status elites who were wiped out by the Spanish. So khipuyu stops, and anything modern people do is just almost like a triviality.

[Regina Barber]

I assume she doesn't feel that way at all.

[Nell Greenfieldboyce]

Not at all. Not at all. Like, last year, she was invited to this community called Jacul. It's this remote village in the Andes that has khipus.

[Sabina Hyland]

They asked me to look at it. They'd never shown their khipus to outsiders before.

[Nell Greenfieldboyce]

And for one thing, these ancestral khipus she saw had human hair tied to them, which the people told her was like a signature of the maker.

[Regina Barber]

Ooh, this is fascinating.

[Nell Greenfieldboyce]

Yeah, and these khipus also had a lot of tassels on them. And she told me that ancient Inca khipus can have tassels on them too. And so she's hoping to go back next year and learn more about the tassels and, like, what kind of meaning they have by just, you know, talking to people there.

[Regina Barber]

I know, talking to people, it's a radical notion, very old school.

[Nell Greenfieldboyce]

It's not like using AI. It's just talking with people.

[Regina Barber]

Nell, thank you so much for bringing us the story.

[Nell Greenfieldboyce]

Oh, it's my pleasure.

[Regina Barber]

This episode was produced by Rachel Carlson and lightly edited by our showrunner, Rebecca Ramirez. Tyler Jones and Nell checked the facts. Maggie Luthar was the audio engineer. Beth Donovan is our senior director, and Colin Campbell is our senior vice president of podcasting strategy. I'm Regina Barber. Thank you for listening to shortwave from npr.

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