Status: A hoax (perhaps?) based on a real experiment
Henry Rosenbaum emailed me with the following description of a hoax, followed by a question:
For 30 years, from the mid-1960's, I lived in central Michigan, about a four hour drive from Toronto, Ontario, Canada, where my wife and I often visited for weekends. I well recall an exhibit at one of the major museums that featured an enclosed cage/environment with a number of mice and a descriptive explanation to the effect: The mice were limited in the amount of space they were afforded, yet they were provided all the food and water their colony required, regardless of its numbers. The display stated they had at first healthily thrived and multiplied but as their supported numbers greatly increased without any increase in territory, the members became first combative and then homosexual, with the ultimate dying out of the colony despite the unlimited physical resources. Of course this was to illustrate what (perhaps as Malthus had predicted?) would ultimately happen to man if population growth was not checked.
I believed it was shortly after I left Michigan (mid-1990s) that I read in a West Coast newspaper that the museum had acknowledged the exhibit was a hoax made up in the minds of its (two, as I recall) researchers. I neglected then to clip the article and have for the last couple of years been unsuccessfully trying to re-locate the information of the hoax and its details. I had hoped it might be mentioned in your book and then attempted to research your web site under both mice and rats with variations as well as under several subject matters, all without success. I would appreciate if you could point me in the right direction.
I had never heard of this experiment/museum exhibit before (which is why it's neither in my book or on the site). Does it ring a bell with anyone?
Comments
There is a paper by John B Calhoun called "Population Density and Social Pathology." (Calhoun, John B. 1962.
Each burrow contained lines of 4 pens in a row, with openings between so that rats could pass from pen #1 to #4, by passing through #2 and #3 in between. Each pen had food, water and nesting material; but gradually pens #2 and #3 in each row became the centre of social activity, regardless of resources, simply because they were in the middle.
Things went further wrong when it was found that the subdominant rats matured earlier than the dominant males. This meant that the subdominant ones left the end pens early, leaving the dominant males with no-one to fight. These males in the end pens thus became even more aggressive and territorial, so increasing the crowding in the middle pens - even though, as at the start, there was plenty of room, food etc. for all of them.
The crowding in the middle pens induced fighting, aberrant sexual behaviour (meaning anything untypical, not necessarily homosexual), random violence, intrusion on lactating females, various health problems, disrupted behaviour patterns, and neglect of young.
The "mice in the museum" exhibit sounds interesting; perhaps they were trying to reconstruct Calhoun's experiment, or do a variation on it? The whole issue of overcrowding with any social species (such as rats in pens, or humans in slums) is about more than just space.
When I got it back there was only one comment on the whole paper. The tutor had objected to me describing the observed homosexual behaviour as 'abnormal'.
http://www.popline.org/docs/0152/620189.html
I wonder about the genetic quality of rodents raised in captivity. They are descended from the ones that weren't smart enough to get away.
1. Inbreeding can cause serious mental and behavioural aberrations in rodents. (And it only takes about two generations for the aberrations to surface)
2. Inexperienced mothers will frequently kill and eat their first litter. Experienced mothers will frequently kill and eat their babies if something is wrong with them--if they are underweight, retarded, insane, or too sickly or malformed to live (all conditions which could easily be caused by inbreeding). And they can sense these problems in their babies easily and quickly.
You had a tank full of gerbils of both sexes all descended from one pair, dude. Your experience does not bear out the Calhoun experiment; it merely bears out the practice of segregating males from females, and especially if they are closely related.
It may also be worth noting that rodents who are advanced in age can readily go senile (holes actually form in their little cerebellums) and engage in some very disturbing behavior. It's quite common. I once had a five-year-old hamster--very old for a hamster--who started going in circles continually in his last days, eventually catching his little hind leg in his wheel and continuing to circle until he had twisted it off. After I freed him, he continued to limp in circles all night, and died the next day.
"if the situations were shown to be equivolent"
I just needed to express my admiration of that pun, since noone else saw fit to.
http://www.amazon.com/Tragedy-Mouse-Utopia-Ecological-Commentary/dp/1412056330
There is an answer to Christopher from Joplin's (hopefully) humorous question "How do you explain San Fransisco?" It was the major demobilization point for the Pacific theater after WW II. Many who could not or preferred not to go home after discharge stayed there. Among the group that "could not or preferred not to" were homosexuals, who found San Fransisco's very liberal attitude towards all manner of differences (some of those considered improper if not illegal elsewhere) to be hospitable. The fewer homosexuals who'd settled there for this reason previously provided a situation that attracted more. After the beginning of open acceptance of this sort of difference during the 60's, many more were attracted and moved there. (http://www.greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id=007Cix)
http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1644264&blobtype=pdf
Unfortunately for me and my grade, my experiment partner kept the animals over Christmas break, delegated the task of feeding them, which didn't happen, and all but one were dead or killed on his return. I was spared the scene.