Augmented Things You Didn’t Know You Didn’t Know—Madalena Cruz-Ferreira SpecGram Vol CLXII, No 4 Contents Now Playing at the Move-α-plex!—The Trill Hunter & Conan the Librarian

Language Evolution and the Acacia Tree

by Sean Geraint

Last year, renowned treethnographer Garik Roblerks noticed that two books on the evolution of language had strikingly similar covers. Both Christiansen & Kirby’s Language Evolution and Fitch’s The Evolution of Language boasted an acacia tree in the sunset. On closer inspection, these turned out to be different pictures of the same tree.


A comparison of the books
by Christiansen & Kirby (left) and Fitch (right)

Having spent a year tracking trees in Kenya, I can confirm that the tree is from Maasai Mara National Reserve. The tree has attracted a lot of attention since its entrance into the glamorous world of book cover design, and I observed some excited undergraduate linguists tying ribbons to its branches with messages such as “Thanks for the episodic memories” and “Dolphins next, please”.

Of course, this prompts the questionwhat is the link between language evolution and acacia trees? Obviously, there was some subconscious (perhaps innate?) connection in the minds of the authors. The first step was to look at the distribution of acacia trees around the world. Strikingly, the distribution of acacia trees looks remarkably like the distribution of tonal languages. Indeed, the countries in which the acacia tree Acacia nilotica grows are significantly more likely to have tonal languages (Chi-squared with Yates’ continuity correction for having spent ten hours nudging the data around = 47.1, df = 1, p < 0.0001, data from the Crop Protection Consortium and the World Atlas of Language Structures).


Distribution of tonal languages


Distribution of acacia trees

Quite remarkable, but this would just be a pointless, spurious statistic without a causal mechanism. I was then reminded that acacia trees produce tryptamines such as Dimethyltryptamine (DMT). These are psychedelic compounds that can cause sensory enhancement, euphoria, immersive experiences and radical perspective shifting. These are, of course, not only extremely useful in coming up with hypotheses about the origins of language, but exactly the kinds of mind-altering substances that we could expect to cause the rapid evolution of language in the first place.

So, I propose the acacia hypothesis of language evolution: Some primates got high and thought it would be a laugh to try and refer to objects using arbitrary signs.

However, the effects of acacia trees on culture have been felt more recently: Shanon (2008) suggests that Moses was under the influence of this naturally occurring smack when he heard the burning bush (an acacia!) talking to him. This is direct evidence for a link between acacia trees and linguistic inspiration.

Language evolution trees in the lab

In order to investigate the effect of acacia trees on language evolution, I extended an iterated learning experiment (Kirby, Cornish, Smith, 2008):

Method

  1. Recruited 1,000 participants (12% excluded because they “had seen the TV mini-series”)
  2. Exposed participants to a random language
  3. Got them to recall the language
  4. Passed this recalled language on to the next participant as their input

There were two conditionsa control condition and a condition where the participants were administered 50mg of Dimethyltryptamine. I then measured the amount of composystemalexity at each generation for both conditions.

Results

The DMT condition performed above the control group for the majority of generations, suggesting that the acacia tree really does have an effect on cultural transmission (see below).

The composystemalexity drops significantly in the last generation for the DMT group. Looking at the 27 words produced in the last generation, the control group looks as you would expect, although a higher WWMI* than usual:

nanarenanabanana
pajamaninjanabinjana
bonjanazombanabombana
billbenweed
pogleandypandy
ragtagbobtail
boobakikiblicket
wugdaxleedle
johnmarybook

The words in the DMT condition were seemingly random clusters of letters and symbols. They had, quite possibly, just lost it. However, I made a startling discovery when I lined up the words one after another:

........................................8ZO....Z..Z............................D
..................................8OOMMMZ.Z.ZDOD8M8NMZOZ..O.Z..................D
.............Z.O....ND8..8ZZ..O8.ZMMNNMMNMMMMNMMMMMMMMMDNONNDMDOOD.............D
...............8MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMNDD..O......D
...............Z8MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM8NNO88
................8..ZN8.MMMDNMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM8
......................N...ZNMM.NN.MZ8NNMMMMMNMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM8
.........ZMMMMN8..Z..Z.....8NDZNN8....O.D.O8MNMMMMMMMNMMMMMMMMMMMMMMMMMMMMMM.MMD
.........NMMN8MMM8MZD8.......DZ..NMMN......ZZMMMMM.DNMNMMMMMMZNMMMMMMMN8NNND8Z88
.....................N.D.Z............MMMN..MMM.....DMZ.ODMMMMMMZ8..ZOZ88MD....8
........................ON................ONMM.N.....MMMOZ.DMNZ....Z.Z......Z..D
............................N=..............MM........M.MMNOMZ...............Z.D
..............................M.............MD.........MOMMM...................D
..............................NDNMMMD......NMMM........MMMMM.8.................D
......................................MMMD....NMM...MMMMM....ZDD...............D
...................=...........................ZMMMMMN8........................8
..............:,,,,,,,,:=.......................MMM............................8
............:,,,,,,,,,,,,:......................DMM...........................Z8
...........::,,,,,,,,,,,,:~......................MMN........................ZZZ8
..........=:::::::::::::,::=.....................MMM........................ZZZ8
..........~::,,,,,,,,,,,,::=.....................MMM......................ZZZZZ8
..........=:,,,,,,,,,,:::::.....................ZMMM.....................ZZZZZZ8
...........~::::::::::::::=.....................OMMM....................ZZZZZZZ8
............~~::::::::::~........................MMM........................ZZZ8
..............==~~~~~~=..........................MMM...........ZOODDDNNNNNNDDD88
DDDDDD888888OZOZ..................ZZOOOO888888888DMMMDDDDDDNNNNNNNNNNNNNNMMMMMM8
NNDDDDDDDD88888888888888888888888DDDDDDDD8DDDDDDDDMMMNNNNNNNNNNNNNNNNMMMMMMMMMM8

The language had transcended all communicative pressures and evolved to fit the cognitive biases of its users. It turns out that an important bias may be acacia trees in the sunset.

References

Christiansen, M. and Kirby, S. (2003) Language Evolution. Oxford University Press.

Fitch, W. T. (2010) The Evolution of Language. Cambridge, UK: Cambridge University Press.

Kirby, Cornish, Smith (2008) “Cumulative cultural evolution in the laboratory: An experimental approach to the origins of structure in human language.” PNAS, 105(3) 10681-10686.

Shanon, B. (2008) “Biblical Entheogens: a Speculative Hypothesis.” Time and Mind, 1(1) 51-74.



* Watch With Mother Index.

Augmented Things You Didn’t Know You Didn’t KnowMadalena Cruz-Ferreira
Now Playing at the Move-α-plex!The Trill Hunter & Conan the Librarian
SpecGram Vol CLXII, No 4 Contents