Amazonian Beer Drinking Networks Revealed by Anthropologists

The Physics arXiv Blog ^ | November 25, 2013

[anymouse]

The way the Tsimane tribe of the northern Amazon host beer drinking events offers important clues about the nature of their society, say anthropologists

The indigenous Tsimane hunter-gatherers of the northern Amazon are probably the best studied native community in the world. About ten years ago, a team of US researchers began a decade-long research program to better understand the way these people develop, evolve and socialise as part of a unique farmer-forrager community .

The so-called Tsimane Health and Life History Project has thrown up some fascinating insights into the hunter-gatherer lifestyle. Last year, for example, the team revealed that the Tsimane (prounounced chee-MAH-nay) do not succumb in the same way as westerners to heart problems as they age. A fining that led the researchers to conclude that cardiovascular disease is probably a phenomenon of modern societies.

Now the same group has analysed the social network that exists within this society to study one of the great puzzles of evolutionary theory—the emergence of altruism. Why do people sometimes help others at their own expense?

Altruism is difficult to reconcile with the idea of the selfish gene—that behind every act is the ulterior motive of increasing the chances of reproduction at the expense of others. Theorists have developed a number of models to explain the conditions in which one person might consider it advantageous to help another. The question is whether these theories bear any relationship to reality.

Today, Hillard Kaplan at the University of New Mexico in Albuquerque and a few pals say they’ve gained a unique insight into this question by studying beer drinking networks in a Tsimane village in lowland Bolivia.

The key idea here is that hosting a beer drinking party involves a significant investment in time and resources. So when one family hosts another, what kind of obligation does this place on the guests to return the favour?

There are some 11,000 Tsimane people in about 90 villages in the forested region between the foothills of the Andes and the wetland-savannas of the Llanos de Moxos. Kaplan and co studied the beer drinking culture in one village of about 200 people made up of 35 families.

Beer drinking events are an important part of Tsimane culture. They prepare beer from manioc, a kind of sweet potato. The manioc is peeled, sliced and boiled in water over an open fire for several hours.

The mixture is then poured into wooden pots to ferment, a process helped along by the Tsimane themselves who chew the boiled vegetable and spit it into the mix. The fermentation lasts up to 6 days and produces a beer that is up to 4 per cent alcohol.

Clearly, hosting a beer drinking event requires a significant investment in time and resources. At these parties. the Tsimane consume the beer from a single hollowed gourd which is passed around until empty. These events build social and familial ties and the guests often return the favour at a later date.

The data gathering for these events isn’t entirely straightforward. Kaplan and co’s approach was to interview people over a 16 week period, asking them who hosted these events and who attended. That allowed Kaplan and co to construct a network linking guests and hosts for each event and to record how these favours were later returned, a phenomenon that anthropologists call reciprocity.

The team then looked for correlations between the rate of hosting and other data such as the distance that people had to travel to the events and to kinship, whether the hosts and guests were closely related

The results show a good deal of reciprocity in Tsimane society. For example, distance and kinship are good indicators of how often one family hosts another. In other words, the Tsimane are more likely to host close neighbours and close family than other people.

That’s just as the researchers expected. There is a clear evolutionary benefit in helping family members and in maintaining good relations with close neighbours.

But the results also throw up a puzzle: the Tsimane also host unrelated families and people from much further away than expected, at a rate that is difficult to explain. And these unexpected beer hosting favours are often, but not always, returned much more quickly than with close family or neighbours, usually within three days or so.

Kaplan and co speculate that these events are triggered by other kinds of favours that they were unable to record in their survey—things like help in the fields, help with food preparation, mate searches or help with political matters.

These are all key aspects of complex societies that must be carefully managed to gain the greatest the benefit.

That will sound familiar to many readers who will undoubtedly have their own beer drinking networks. While the details and timescales may vary from one culture to another, the same factors underlie reciprocity in this culture as in the one you’re probably familiar with. And therein lies a fascinating lesson.

[anymouse]

"Beer: The cause of, and solution to, all of life's problems." - Homer Simpson

[Paladin2]

These guys got micro breweries?

[blueunicorn6]

“Ninety nine gourds of manioc mash in the hut, ninety nine gourds of mash. Take one down and pass it around....ninety eight gourds of manioc mash in the hut!”

[blueunicorn6]

“Who chew the boiled vegetable and spit it into the mix.”

You don’t want to know how they make stew.

[GraceG]

Mmmmmmmm Beeeeerrrrrr

[Jack Hydrazine]

Do they play that old beer drinking game, “Hi Bob!”?

[moovova]

At the local AAA (Amazonian Alcoholics Anonymous) meeting;

“Hello, my name is Tclaxticotl, and I’m an alcoholic.”

[Eagles6]

Beer drinking networks? Obviously a highly advanced civilization.

[Bender2]

Re: Beer drinking events are an important part of Tsimane culture. They prepare beer from manioc, a kind of sweet potato. The manioc is peeled, sliced and boiled in water over an open fire for several hours.

The mixture is then poured into wooden pots to ferment, a process helped along by the Tsimane themselves who chew the boiled vegetable and spit it into the mix. The fermentation lasts up to 6 days and produces a beer that is up to 4 per cent alcohol.

Gadzooks-- Chew and spit back! All that.. and only "up to 4 per cent alcohol?"

My system of recycling all the brew I drink... makes for a much high kick, especially on the 8th and 9th go around!

Well, "Chew and spit back!" does explain the Monday Night Football Clinic... the Deadskins put on highlighting Mike Sheehan's system of coaching and rat impersonations.