New research paper about cooperation in groups of Saami reindeer herders

People rely on one another in fundamental ways, but cooperation in groups can be fragile. Every day, we face tensions between acting in a socially responsible manner and following our own self-interest. These situations are called social dilemmas and they come in varying shades of subtlety, from littering and eBay to overpopulation and climate change. Overcoming these dilemmas can make all the difference, especially for marginalised groups such as pastoralists – people who make their living from herding animals.

Pastoralists use about a quarter of the world’s land for grazing their herds. Nowadays, all over the world, governments are privatising many of their pastures, and so herders must work together in increasingly fragmented places.

We wanted to learn how groups of Saami reindeer herders living in Norway’s Arctic Circle worked together. Our study, just published in the journal Human Ecology, found that cooperation pivoted around the ‘siida’: a group of herders—often family members—sharing pastures and migration routes. Smaller siidas were more cooperative, but the presence of closer family members did not affect cooperation.

While interviewing the reindeer herders, we gave them vouchers for five litres of petrol and asked how much of it they wanted to contribute to their siida. The amount they’d receive in return depended not only on how much they chose to give but also on how much everyone else in their group gave.

This economic situation is known as a public goods game. A public good is any resource (or ‘good’) that’s open for anyone to access without diminishing through use. This blog post, for example, is a public good. Your enjoyment (or otherwise) of it doesn’t stop anyone else from reading.

In a public goods game, a group of people choose how much of their money to share with everybody else. The experimenters increase whatever was donated to the group’s pot (we multiplied donations by 50 percent) and then distribute the final amount equally among all players, regardless of how much each person contributed.

This kind of experiment is very much a caricature of real-life dilemmas about how best to make decisions given how other people are behaving, but caricatures are helpful shortcuts to understanding cooperation – especially in places like Norway where everything costs a lot of money and learning how reindeer herders work together out in the pastures would require decades of observation (and a hardiness to the despair of winter that I probably can’t muster).

In theory, people make their donation decisions based on how much they expect to get back. In economic parlance, this is the ‘marginal per-capita return rate’. Groups with fewer members tend to have higher return rates and so they should donate more. This is what we found:

Petrol donations by marginal per-capita return rate

Smaller groups could expect to receive more in return for every litre they donated and this corresponded with larger donations in our experiments.

We also asked people about how often they took part in a set of activities – tasks like herding, slaughtering and making handcrafts (duodji, in the Northern Saami language). Herders directed most help towards their own siida, though helping people in other siidas wasn’t unknown. This makes sense, since siidas might rely on one another to repair shared fences or to separate reindeer when their herds mix.

Cooperation, as reported by the herders we interviewed

The study is available to read for free here:

For the overtly nerdy, we’ve also released our data and analysis code here:

New research paper about Saami reindeer herders and gift-giving

I’m enormously pleased to say that I have a new bit of research published. The paper is about gift-giving in a group of reindeer herders living in Norway. It’s the culmination of nearly two and a half years’ worth of work – from our initial planning, though some months of hanging out in the (surprisingly warm) arctic, to endless rounds of statistics and writing and revising and statistics and *facepalming* and statistics and *headdesking* and statistics and revising.

The paper itself is published in a journal called Behavioral Ecology but because of funding constraints we weren’t able to make it open access – to my great chagrin (but you can download a PDF for free here or read it online here, or feel free to email me if you want a copy).
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New paper about how sibling competition and mortality risks affect birth intervals

My very first contribution to the collected sum of human knowledge has just been published in the Journal of Evolutionary Biology. The paper is called: “A Dynamic Framework for the Study of Optimal Birth Intervals Reveals the Importance of Sibling Competition and Mortality Risks” and you can read it online or download a PDF. I’ll talk about the main results in this post.

paper header 2
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My review of the Crick Lecture 2014 – ‘Genetic control and the mammalian radiation’

I reviewed last November’s Crick Lecture at the Royal Society on behalf of BioNews. Dr Duncan Odom spoke about mammals, genes, a branch of biology called ‘comparative functional genomics’ and how we all owe everything to tiny shrews. I also took the opportunity to have a moan about simplistic sloganeering and the rights of marginalised forest-dwelling people. Have a read.

Becoming Human: Our Changing Views of Neanderthals

Neanderthals are cool. They cared for sick and elderly, buried their dead (possibly with funeral rites), wore clothes and jewellery, made art and had sex with our ancestors.

I wrote an article for Shot of Science about how our perceptions of Neanderthals has been changing since their remains were first discovered in the 1800s (before On the Origin of Species, incidentally).

Have a read here.

Gene from extinct species allows Tibetans to live at high altitude

The roof of the world, north of the Himalayas, stretches over two and a half million square kilometres. It is inhospitable, arid and permafrosted. When it rains, it mainly hails. It’s the highest place on the planet where you can stand on flat ground and be near the heavens, and standing there will thicken your blood. Unless you carry the EPAS1 gene.

This gene stops you over-producing haemoglobin – the oxygen-carrier in red blood cells. Too much haemoglobin raises blood pressure and, with it, the risk of stroke, among other bloody things.

This gene came from an ancient, extinct subspecies of human called the Denisovans. We know this because scientists sequenced Denisovan DNA four years ago. This DNA came from a fragment of a pinky and two teeth found in a cave.

The ancestors of today’s Tibetans had sex with Denisovans. Genes were passed around. The useful ones remained. This allows Tibetan people to survive on the roof of the world.

I wrote about the science for this week’s BioNews. Have a read.

Replica of Denisovan pinky bone (Source: National Geographic)

We Burn Daylight

My friend Kathleen Bryson and I co-wrote and co-directed (and co-starred in) a filmpoem with the editing wizardry of Kimmo Moykky and the cinematographic skills of Ollie Drackford.

Poem words below the video. The text of the poem is released under a Creative Commons Attribution-Noncommercial-ShareAlike License so feel free to do with it what you will (as far the license allows…).

We Burn Daylight from Kathleen Bryson on Vimeo.

We Burn Daylight

I heard the foxes mate last night, full sting,
all coil and pleasure crawl, all bitter pierce and tuft.

I made you into a hedgehog instead,
tied twigs in your hair, and you let me laugh;
no shaman blossomed by berry blood,
serious with stag horns and pinebranch shadows.
You are at the very least a tolerant man.

I’ll sing like foxes sing, I think,
orange wounds and sultry bites;
you’re tied to twigs that might not scratch you, or they might
not cut you, or they might.

The foxes with their tails scooped from fires
The foxes with their red hair and their cauls
The foxes with their teeth now hidden axes
You tried not to think of them at all.

I do not care if they call me home.
I must have time to pick away your twigs
and count your freckles, scratch your hands by chance.
I want you to hear the foxes sing.

. . .

What will it come to mean, the mournful sting
of pollen on the breeze, the twilight
shivers through his hair?

No man could have been a man,
who chose this creature, vulpine
on her haunches, her thick brow
sheltering her flowstone eyes,
belly ripened, juicy with life.

She tends his body in this shallow pit.
Stubby fingers paw at yarrow and lay grape
hyacinth on his collapsed temple.

Here is the first grave, bedded with groundsel,
flecked with the shadows of Shanidar Cave.

Nobody knows what it meant – a burnt ochre
bouquet, tousled breaths, this first act
of devotion – an explosion
into humanity, into lives
full of unfossilised moments.

There is no word yet for the kick of her
almost-human child, no word for why
she soothes his hair from the taunts of the wind.

She opens her mouth, as if to sing.

Fishing in the gene pool for Vikings: A review

We are sea-rovers, genetically. That is to say, you’re probably a Viking – but that’s not very exciting because so are most Europeans. If you’re from another part of the world and reading this, I imagine you aren’t so fussed about Viking heritage.

Vikings were fishers and merchants forced onto the open seas to escape their over-populated land in search of a livelihood. Vikings are romanticised and mythologised and made into TV shows and video games (both new and old). People pay good money to find out if they were born from Viking stock. Eddie Izzard subjected himself to a BBC programme about his genetic ancestry, discovering that he, like many others, descends partly from Vikings. So the essence of the question is not whether you are a Viking, but how much of a Viking you are.
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