The cranial plasticity issue: a reassessment?

[Jacques Cinq-Mars]

All,

Unless I am completely wrong, the following should make a few waves:

Published online before print October 8, 2002
Proc. Natl. Acad. Sci. USA, 10.1073/pnas.222389599

A reassessment of human cranial plasticity: Boas revisited

Corey S. Sparks * and Richard L. Jantz

*Department of Anthropology, Pennsylvania State University, 409 Carpenter Building, University Park, PA 16802; and {ddagger}Department of Anthropology, University of Tennessee, 250 South Stadium Hall, Knoxville, TN 37996

Edited by Henry C. Harpending, University of Utah, Salt Lake City, UT, and approved August 30, 2002 (received for review July 1, 2002)

In 1912, Franz Boas published a study demonstrating the plastic nature of the human body in response to changes in the environment. The results of this study have been cited for the past 90 years as evidence of cranial plasticity. These findings, however, have never been critiqued thoroughly for their statistical and biological validity. This study presents a reassessment of Boas' data within a modern statistical and quantitative genetic framework. The data used here consist of head and face measurements on over 8,000 individuals of various European ethnic groups. By using pedigree information contained in Boas' data, narrow sense heritabilities are estimated by the method of maximum likelihood. In addition, a series of t tests and regression analyses are performed to determine the statistical validity of Boas' original findings on differentiation between American and European-born children and the prolonged effect of the environment on cranial form. Results indicate the relatively high genetic component of the head and face diameters despite the environmental differences during development. Results point to very small and insignificant differences between European- and American-born offspring, and no effect of exposure to the American environment on the cranial index in children. These results contradict Boas' original findings and demonstrate that they may no longer be used to support arguments of plasticity in cranial morphology.

To whom correspondence should be addressed.
E-mail: css186@psu.edu.

www.pnas.org/cgi/doi/10.1073/pnas.222389599

http://www.pnas.org/cgi/content/abstract/222389599v1

[colin]

Hi Jacques
I'm a bit puzzled by this, but perhaps I'm missing something.
As there is no such thing as a single American or European "environment" (there would be a world of difference between the environment experienced in 1912 by a kid in the Bronx and a rich kid in California; ditto a Scottish sheep farmer and a Greek olive grower) we surely shouldn't expect Boas' study to tell us anything very useful about the effect of the American environment on cranial development anyway?

On the other hand if we went  back to the 1912 east end of London we might have a hard time telling a victim of rickets that the environment (in a broad sense) had no effect on cranial development.
Cheers
Colin

[junkscience]

I have the complete study of Corey And Jantz about Boas data.

You can donwload here:

http://www23.brinkster.com/acacias/frank.pdf


Cheers!!

[Isabelle]

When I tried to get to the article I got the following error message:

HTTP1.1 STATUS 403 Remote Access to this object forbidden This file cannot be directly accessed from a remote site, but must be linked through the Brinkster Member's site.

regards,
Isabelle

[junkscience]

When I tried to get to the article I got the following error message:

HTTP1.1 STATUS 403 Remote Access to this object forbidden This file cannot be directly accessed from a remote site, but must be linked through the Brinkster Member's site.

regards,
Isabelle

Don worry, try this links:

http://etd.utk.edu/2001/SparksCorey.pdf

and here:

http://www.pnas.org/cgi/reprint/222389599v1?ijkey=f3uGSmr3wB0r.


Bye