nhaliday + male-variability + antiquity   8

Does left-handedness occur more in certain ethnic groups than others?
Yes. There are some aboriginal tribes in Australia who have about 70% of their population being left-handed. It’s also more than 50% for some South American tribes.

The reason is the same in both cases: a recent past of extreme aggression with other tribes. Left-handedness is caused by recessive genes, but being left-handed is a boost when in hand-to-hand combat with a right-handed guy (who usually has trained extensively with other right-handed guys, as this disposition is genetically dominant so right-handed are majority in most human populations, so lacks experience with a left-handed). Should a particular tribe enter too much war time periods, it’s proportion of left-handeds will naturally rise. As their enemy tribe’s proportion of left-handed people is rising as well, there’s a point at which the natural advantage they get in fighting disipates and can only climb higher should they continuously find new groups to fight with, who are also majority right-handed.

...

So the natural question is: given their advantages in 1-on-1 combat, why doesn’t the percentage grow all the way up to 50% or slightly higher? Because there are COSTS associated with being left-handed, as apparently our neural network is pre-wired towards right-handedness - showing as a reduced life expectancy for lefties. So a mathematical model was proposed to explain their distribution among different societies

THE FIGHTING HYPOTHESIS: STABILITY OF POLYMORPHISM IN HUMAN HANDEDNESS

http://gepv.univ-lille1.fr/downl...

Further, it appears the average left-handedness for humans (~10%) hasn’t changed in thousands of years (judging by the paintings of hands on caves)

Frequency-dependent maintenance of left handedness in humans.

Handedness frequency over more than 10,000 years

[ed.: Compare with Julius Evola's "left-hand path".]
q-n-a  qra  trivia  cocktail  farmers-and-foragers  history  antiquity  race  demographics  bio  EEA  evolution  context  peace-violence  war  ecology  EGT  unintended-consequences  game-theory  equilibrium  anthropology  cultural-dynamics  sapiens  data  database  trends  cost-benefit  strategy  time-series  art  archaeology  measurement  oscillation  pro-rata  iteration-recursion  gender  male-variability  cliometrics  roots  explanation  explanans  correlation  causation  branches 
july 2018 by nhaliday
Y-chromosome crash | West Hunter
there probably wasn't vast reproductive inequality ("17 to 1! woah") in the Bronze Age, and there wouldn't have to be to explain observed genetic patterns

https://westhunt.wordpress.com/2014/06/26/kings-of-the-stone-age/
https://westhunt.wordpress.com/2014/08/30/we-three-kings/
https://westhunt.wordpress.com/2014/09/07/the-genghis-khan-effect/

comment on TFR gradients in Malthusian conditions: https://westhunt.wordpress.com/2015/03/21/y-chromosome-crash/#comment-67790
“By contrast, the average number of surviving children for the majority of men was probably somewhere between zero and one – despite that they were having sex and babies.”

Fuck me, that’s obviously ridiculous. In real life, take a peasant village in England: if your model were correct, you’d have surname turnover every couple of generations. But that didn’t happen.

Here’s a model that’s at least in the ballpark: there was some class differential in fitness. The poorest, landless laborers, had a TFR below replacement, but not by a tremendous amount: 1.6? Most peasants were close to break-even, upper farmers did better than break-even, Other groups were mostly too small in number or too urban (population sinks) to matter. Overall TFR was of course break-even over the moderately long haul, in a sloppy way, with occasional epidemics and crop failures.
west-hunter  sapiens  antiquity  regularizer  speculation  gavisti  explanation  thinking  🌞  sex  gender  male-variability  winner-take-all  inequality  pop-structure  science-anxiety  scitariat  nietzschean  sexuality  gender-diff  null-result  deep-materialism  EEA  history  multi  aDNA  archaeology  conquest-empire  china  asia  genetics  genomics  poast  fertility  medieval  britain  demographics  malthus  class  correlation  blowhards  traces 
november 2016 by nhaliday

bundles : dismalityglobepatterns

related tags

aDNA  age-of-discovery  anthropology  antiquity  archaeology  art  asia  bio  blowhards  branches  britain  causation  chart  china  class  cliometrics  cocktail  commentary  competition  conquest-empire  context  correlation  cost-benefit  cultural-dynamics  culture  data  database  deep-materialism  demographics  dropbox  early-modern  ecology  EEA  EGT  equilibrium  europe  evolution  evopsych  explanans  explanation  farmers-and-foragers  fertility  game-theory  gavisti  gender  gender-diff  gene-flow  genetics  genomics  geography  gnxp  group-selection  GT-101  history  inequality  iteration-recursion  latin-america  male-variability  malthus  measurement  medieval  mediterranean  migration  models  moments  multi  new-religion  nietzschean  null-result  org:anglo  org:mat  org:rec  oscillation  peace-violence  poast  pop-structure  population-genetics  preprint  pro-rata  q-n-a  qra  race  regularizer  revolution  roots  sapiens  science-anxiety  scitariat  sex  sexuality  shift  smoothness  sociology  speculation  strategy  study  stylized-facts  summary  thinking  time-series  traces  trends  trivia  unintended-consequences  war  west-hunter  winner-take-all  🌞 

Copy this bookmark:



description:


tags: