Culture evolution by R Alexander Bentley
Almost by definition, bpopular cultureQ reflects the effects of most people imitating those aroun... more Almost by definition, bpopular cultureQ reflects the effects of most people imitating those around them. At the same time, trends and fashions are constantly changing, with future outcomes potentially irrational and nearly impossible to predict. A simple null model, which captures these seemingly conflicting tendencies of conformity and change, involves the random copying of cultural variants between individuals, with occasional innovation. Here, we show that the random-copying model predicts a continual flux of initially obscure new ideas (analogous to mutations) becoming highly popular by chance alone, such that the turnover rate on a list of most popular variants depends on the list size and the amount of innovation but not on population size. We also present evidence for remarkably regular turnover on bpop chartsQ—including the most popular music, first names, and dog breeds in 20th-century United States—which fits this expectation. By predicting parametric effects on the turnover of popular fashion, the random-copying model provides an additional means of characterizing collective copying behavior in culture evolution.
In the social sciences, there is currently no consensus on the mechanism by which cultural elemen... more In the social sciences, there is currently no consensus on the mechanism by which cultural elements come and go in human society. For elements that are value-neutral, an appropriate null model may be one of random copying between individuals in the population. We show that the frequency distributions of baby names used in the United States in each decade of the twentieth century, for both males and females, obey a power law that is maintained over 100 years even though the population is growing , names are being introduced and lost every decade and large changes in the frequencies of specific names are common. We show that these distributions are satisfactorily explained by a simple process in which individuals randomly copy names from each other, a process that is analogous to the infinite-allele model of population genetics with random genetic drift. By its simplicity, this model provides a powerful null hypothesis for cultural change. It further explains why a few elements inevitably become highly popular, even if they have no intrinsic superiority over alternatives. Random copying could potentially explain power law distributions in other cultural realms, including the links on the World Wide Web.
We show that the frequency distributions of cultural variants, in three different real-world exam... more We show that the frequency distributions of cultural variants, in three different real-world examples—first names, archaeological pottery and applications for technology patents—follow power laws that can be explained by a simple model of random drift. We conclude that cultural and economic choices often reflect a decision process that is value-neutral; this result has far-reaching testable implications for social-science research.
Human culture has evolved through a series of major tipping points in information storage and com... more Human culture has evolved through a series of major tipping points in information storage and communication. The first was the appearance of language, which enabled communication between brains and allowed humans to specialize in what they do and to participate in complex mating games. The second was information storage outside the brain, most obviously expressed in the " Upper Paleolithic Revolution " – the sudden proliferation of cave art, personal adornment, and ritual in Europe some 35,000–45,000 years ago. More recently, this storage has taken the form of writing, mass media, and now the Internet, which is arguably overwhelming humans' ability to discern relevant information. The third tipping point was the appearance of technology capable of accumulating and manipulating vast amounts of information outside humans, thus removing them as bottlenecks to a seemingly self-perpetuating process of knowledge explosion. Important components of any discussion of cultural evolutionary tipping points are tempo and mode, given that the rate of change, as well as the kind of change, in information storage and transmission has not been constant over the previous million years.
—In this paper, we test the robustness of emotion extraction from English language books publishe... more —In this paper, we test the robustness of emotion extraction from English language books published in the 20 th century. Our analysis is performed on a sample of the 8 million digitized books available in the Google Books Ngram corpus by applying three independent emotion detection tools: WordNet Affect, Linguistic Inquiry and Word Count, and a recently proposed 'Hedonometer' method. We also assess the statistical robustness of the extracted patterns as well as their outputs on specific parts of speech. The analysis confirms three main results: the existence of recognizable periods of positive and negative 'literary affect' from 1900 to 2000, a general decrease in the usage of emotion-related words in printed books that lasts at least until the 1980s, and, finally, a divergence between American and British books, with the former using more emotion-related words from the 1960s.
—In this paper, we test the robustness of emotion extraction from English language books publishe... more —In this paper, we test the robustness of emotion extraction from English language books published in the 20 th century. Our analysis is performed on a sample of the 8 million digitized books available in the Google Books Ngram corpus by applying three independent emotion detection tools: WordNet Affect, Linguistic Inquiry and Word Count, and a recently proposed 'Hedonometer' method. We also assess the statistical robustness of the extracted patterns as well as their outputs on specific parts of speech. The analysis confirms three main results: the existence of recognizable periods of positive and negative 'literary affect' from 1900 to 2000, a general decrease in the usage of emotion-related words in printed books that lasts at least until the 1980s, and, finally, a divergence between American and British books, with the former using more emotion-related words from the 1960s.
The neutral model of cultural evolution, which assumes that copying is unbiased, provides precise... more The neutral model of cultural evolution, which assumes that copying is unbiased, provides precise predictions regarding frequency distributions of traits and the turnover within a popularity-ranked list. Here we study turnover in ranked lists and identify where the turnover departs from neutral model predictions to detect transmission biases in three different domains: color terms usage in English language 20th century books, popularity of early (1880–1930) and recent (1960–2010) USA baby names, and musical preferences of users of the Web site Last.fm. To help characterize the type of transmission bias, we modify the neutral model to include a content-based bias and two context-based biases (conformity and anti-conformity). How these modified models match real data helps us to infer, from population scale observations, when cultural transmission is biased, and, to some extent, what kind of biases are operating at individual level.
The Internet is known to have had a powerful impact on on-line retailer strategies in markets cha... more The Internet is known to have had a powerful impact on on-line retailer strategies in markets characterised by long-tail distribution of sales [C. Anderson, Long Tail: Why the Future of Business is Selling Less of More, Hyperion, New York, 2006]. Such retailers can exploit the long tail of the market, since they are effectively without physical limit on the number of choices on offer. Here we examine two extensions of this phenomenon. First, we introduce turnover into the long-tail distribution of sales. Although over any given period such as a week or a month, the distribution is right-skewed and often power law distributed, over time there is considerable turnover in the rankings of sales of individual products. Second, we establish some initial results on the implications for shelf-space and physical retailers in such markets.
Studies of collective human behavior in the social sciences, often grounded in details of actions... more Studies of collective human behavior in the social sciences, often grounded in details of actions by individuals, have much to offer `social' models from the physical sciences concerning elegant statistical regularities. Drawing on behavioral studies of social influence, we present a parsimonious, stochastic model, which generates an entire family of real-world right-skew socio-economic distributions, including exponential, winner-take-all, power law tails
Behavioral Ecology and Sociobiology, 2011
Neolithic Archaeology by R Alexander Bentley
Journal of Anthropological Archaeology, 2013
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Culture evolution by R Alexander Bentley
Neolithic Archaeology by R Alexander Bentley
incoming farmersmeet local hunter-gatherers, with greater or lesser impact. By way of contrast, the authors use isotope analysis in a cemetery beside the Danube to describe a peaceful, well-integrated community with a common diet and largely indigenous inhabitants. Men and women may have had different mobility strategies, but the isotopes did not signal special origins or diverse foodproducing roles.Other explanations attend the variations in the burial rites of individuals and their distribution into cemetery plots.
communities formed of heterogenous identities, though we suggest that such diversity was also found alongside evidence for shared practice at different scales of human life.
River Valley of north-eastern Thailand have
provided a detailed chronological succession
comprising 12 occupation phases. These
represent occupation spanning 2300 years,
from initial settlement in the Neolithic
(seventeenth century BC) through to the Iron
Age, ending in the seventh century AD with
the foundation of early states. The precise
chronology in place in the Upper Mun River
Valley makes it possible to examine changes
in social organisation, technology, agriculture
and demography against a background of
climatic change. In this area the evidence for
subsistence has been traditionally drawn from
the biological remains recovered from occupation and mortuary contexts. This paper presents the
results of carbon isotope analysis to identify and explain changes in subsistence over time and
between sites, before comparing the results with two sites of the Sakon Nakhon Basin, located
230km to the north-east, to explore the possibility of regional differences