The example involving caged hens is unlikely to involve any kind of group selection for 'goodness'. See: Aarssen, L.W. (2008) Group-selection for ‘goodness’? An account of chickens, a comparison with plants, and implications for humans. Open Evolution 2: 41-43.
The pdf can be downloaded from:
posted by Lonnie Aarssen
December 22, 2008
About once a month at Sigma Xi headquarters, we liven up the lunch hour with an American Scientist Pizza Lunch talk. In these informal lectures, scientists describe new research to nonscientists. The series is light on jargon but heavy on solid science. Each Pizza Lunch offers an in-depth look at its subject, whether it's bedbugs or the smart grid. Click below to read about and download these talks -- and to subscribe!
JSTOR, the online academic archive, now contains complete back issues of American Scientist from its inception in 1913 (as Sigma Xi Quarterly) through 2005.
The table of contents for each issue is freely available to all users; those with institutional access can read each complete issue.
View the full collection here.