The Mouse Utopia Experiment:
Calhoun, an Ethologist was curious of the behavioral aspects of overcrowding. He set up two experiments, one was a larger pen, he gave them all the food, water, and protection they needed to thrive. The second experiment, was different. The second enclosure that Calhoun constructed gave the mice a drastically smaller amount of space to work with, as well as unlimited food to support the exponentially growing populations. The rats began to form their own social groups and defended this territory as their own. While the population increased in rats, so did the food amount, he eventually brought the population up to 2,200.
Calhoun discovered that once overpopulation began to be an issue, Males were becoming more aggressive in nature and began to be very battered and defensive of their territory. maternal instincts of the rats decreased significantly. The offspring that were abandoned or hardly cared for were unsure of their roles in their society. The rats began to stop reproducing and the females were becoming too stressed out from moving nests so their fertility rate decreased significantly. He called this end stage the “Death Stage.” He knew the outcome of what was to come, extinction. The extinction of this society of rats was an alarming subject regarding overpopulation in other species, Humans perhaps.
Significance:
Many people began to speculate what is to come about the subject of overpopulation in our society. The rats in the initial experiment began to behave like humans, forming their own social groups and behaving in like fashion. Much like humans in city life, forming social groups and living near one another, causing free-space in cities to decrease. There were many people to refute his points the first experiment’s results, Calhoun as a response released his results for the second experiment and began to quote the bible, discussing Armageddon, and the end of civilization. Many people wonder about what will happen to the Earth and social groups once the Earth reaches a point of an inability to sustain such a large population. This is going to be an issue, once our species becomes too large to effectively sustain the rapid increase of population. As medicine improves people will live longer, and in turn will reproduce more.
This experiment effectively shows a possible result of overpopulation: low fertility, more aggressive behavior, and destructive behavioral changes. Calhoun relates these experiments to our possible future once our population grows exponentially. People fear the results that he acquired, and want to be quick to dismiss his points as him being a madman. Calhoun is a very smart person, and he definitely made a breakthrough in behavioral studies and human psychology. Should we fear the future? Only time will tell.
Watch this video to get more in depth explanations of what Calhoun did.
Images from Google.