
Thursday, March 29, 2007
More Random Copying

Wednesday, March 28, 2007
Random Copying
The media is starting to pick up on the Bentley et al (2007) E&HB paper on random copying. Mostly it has been press in the UK (and India) but that could change tomorrow. It is kind of ironic that the message of the paper we wrote is now experiencing the "random copy" effect we describe as a function of the media passing the story on to one another. As it increases in popularity in the press, at least for the period of time before another story pops, it will continue to increase in frequency on science news sites. The frequency of the story itself is predicted by the story. Funny.
Anyways, these are the media references to date.
http://www.inthenews.co.uk/infocus/features/in-focus/changing-fashion-fashionable-$1072208.htm
http://www.spiritindia.com/health-care-news-articles-7830.html
http://www.livescience.com/humanbiology/070328_fickle_fashion.html
http://newswire.ascribe.org/cgi-bin/behold.pl?ascribeid=20070328.094246&time=11%2006%20PDT&year=2007&public=0
http://news.sky.com/skynews/article/0,,30000-1258130,00.html
Monday, March 26, 2007
UFOs

Evolution and Human Behavior
It looks like the Bentley, Lipo, Herzog and Hahn paper Regular rates of popular culture change reflect random copying paper is going to published in Evolution and Human Behavior some time this week. You can download a copy of the paper here:
http://www.csulb.edu/~clipo/papers/BentleyEtAl-2007-RandomCopying.pdf
We are also doing a press release for this through CSULB and the University of Durham. Here's the text of the PR that is slated to go out shortly.
(Cal State Long Beach draft v. 3/26/07)
March 27, 2007 #2007-XXX
Random Copying Influences Popular Trends More Than Rational Choices, Says International Study Group Including Cal State Long Beach Professor
Identifying the next trend-forward thing can be a crucial prediction worth billions of dollars to marketers. Yet, the popularity of things like baby names, music, dog breeds or fashions will change at a constant rate regardless of population size through a process of people randomly copying trends, according to a new study by an international team of academics including a California State University, Long Beach professor.
Controversially, this contradicts classic economic models which believe that people make rational choices about the clothes they wear, the way they dance or the music they listen to.
Researchers at Durham University, England, as well as CSULB, Western Carolina University and Indiana University authored an article titled “Regular rates of popular culture change reflect random copying” that appears in the May issue of the journal Evolution and Human Behavior. It shows that almost all of us are copycats and it is guaranteed that our taste in music or baby names will change at a consistent rate over time, but there is no way of predicting how it will change as it is completely random. New ideas become highly popular by chance alone, and then over time are replaced by others, all through the process of copying with occasional innovation.
Carl Lipo, an associate professor in anthropology at Cal State Long Beach and research scientist at CSULB’s Institute for Integrated Research on Materials, Environments and Society (IIRMES), said that the results demonstrate how relatively simple models can be used to explain remarkably complex phenomena. “What we demonstrate,” he stated, “is that the aggregate effect of simple rules often underlie what we see as organization at higher scales. We don’t need to invoke the idea of some individual or group for patterns to emerge.”
Led by Alex Bentley of the Durham University Anthropology Department, the team looked at the Billboard Top 200 chart and found that it turned over at a constant average rate for over 30 years between 1950 and 1980. The number of albums entering and exiting the chart varied from day to day and month to month, but overall the average stayed fixed at 5.6 percent per month for the full 30-year period. A similar consistent turnover rate was established for the top baby names and dog breeds.
Bentley also is associated with the Centre for the Evolution of Cultural Diversity, funded by UK’s Arts and Humanities Research Council. Psychology Professor Harold A. Herzog of Western Carolina University and biology Professor Matthew W. Hahn of Indiana University also participated in the study.
Their real-world data was matched by computer simulations of a random copying model with 2,000 individuals copying each other from one instant to the next, with a small proportion of innovators (two percent or less). During the simulation, they kept track of the Top 40, Top 100 and other lists of popular trends and monitored how much turnover there was. The model predicted continuous and regular turnover matching the proof of the real-world data from the charts of baby names, music and dog breeds.
How quickly a list will change depends on the size of the list—the more choices people have, the quicker trends become popular or unpopular. However, the research has found that the size of the population does not have an impact on the turnover of lists. Although a higher population means more new ideas are out there, the turnover on a top 100 list does not increase as there is more competition for any particular idea to reach the list.
Marketing professionals who use viral marketing, which spreads information by word-of-mouth through social networks and the Web, often classify people as innovators, early adopters and copiers. “Innovators are the cool ones who don’t bother imitating other people, but instead ‘pump’ new fashions into our world,” Bentley said. “Most are ignored, but some get copied. If the innovator is already a ‘cool’ celebrity, it means something shoots up in popularity much faster than you would predict likely via random copying. However, turnover over time will still be constant.
“The model we have discovered predicts that the turnover of fashion will be proportional to the square root of the proportion of innovators, regardless of population size,” he noted.
Since it is a game of chance, the model cannot predict how any one particular fad will fare, or which trends will become fashionable, just that new trends will definitely emerge at a regular and predictable rate.
The discovery that change is continual and regular under the random copying model means it could be a useful tool to predict change rates as well as distinguish copying from other forms of collective behavior. There are areas in society where random copying is desired. For example, community campaigns to recycle waste benefit by people randomly copying each other’s behavior. However, in other areas such as politics, rational, informed choices are desirable.
# # #
For further information, contact:
- Dr. Carl P. Lipo, California State University, Long Beach, Department of Anthropology; Tel: +01 (562) 985-2393; e-mail: clipo@csulb.edu
- Anne Ambrose, Public Affairs Office, California State University Long Beach, Tel: +01 (562) 985-2582, aambrose@csulb.edu; or Rick Gloady, Tel: +01 (562) 985-5454; e-mail: rgloady@csulb.edu
- Dr Alex Bentley, Durham University, Anthropology Department; Tel: +44 (0)191 334 6198;
- e-mail r.a.bentley@durham.ac.uk
- Media and Public Affairs Office, Durham University; Tel: +44 (0)191 334 6075; e-mail pr.office@durham.ac.uk
Smithsonian Magazine
There is a short article about my field work and research on Easter Island in the most recent issue of Smithsonian magazine.
http://www.smithsonianmagazine.com/issues/2007/april/easter.php
The comments by Joanne Van Tilburg are perhaps the most interesting as they demonstrate her tightly-held beliefs about the prehistory of the island and her reluctance to consider the evidence at it exists. She comes across as though she is putting the story before information, picking and choosing the "facts" as they fit her notions about what "must have" happened. For example, why is it inconceivable that people started making platforms when they first arrived on the island? Sure it makes little sense in 19th century "cultural evolution" framework in which all cultural change goes from "simple" to "complex" in a linear trajectory. But if groups were making platforms and other kinds of ceremonial architecture before they arrived, why would they necessary stop? In fact, this may be one of the first things they would do if the "function" of platforms is religious/honor of ancestor or whatever.
The point is that we have to discard the badly constructed, largely data-free story that has grown up about the island (starting with missionaries) and generate information about the structure and distribution of the archaeological record. Until we do this task, the island will remain a "mystery" -- but perhaps that is ultimate goal of Van Tilburg in the end.
Friday, March 23, 2007
More RCD
For all of you systematics in prehistory fans, philosophers of archaeological science, and mullers of conceptual frameworks for generating knowledge in the past, I just posted a couple of new RCD lectures. http://darwin.anth.csulb.edu/rcd/497/Lectures.html
Enjoy.
Idle Twiddling
Just for kicks, I took an old webcam I had and created a live web feed for my office. Why? I dunno. But you can now peer into the dull activities of an archaeology professor, 7x24. Whoohooo!
http://www.csulb.edu/~clipo/webcam/
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