Today I want to write about sociology… Despite I think this field is just a bunch of gibberish, made-up so sociologist can have a job too, there is a series of experiments run in 60s by John Calhoun that are actually really interesting and worth to discuss. But lets start from the beginning…
At the end of 50s, Calhoun was investigating the effect of overpopulation, and as usual, he started with rats and mice. Among his experiments, the most famous one is “Universe 25“.
It consisted on a large cage of 2.7m2 , with multiple floors. There were tunnels crossing the cage from side to side and 256 pre-build nests, similar to a nice hotel. Each of those nests could accommodate up to 15 mice, so in total, the cage had space for more than 3800 mice. There were also many food-racks around constantly refilled with food and water. For reducing the probability of diseases, every month the cage was cleaned and sterilized. The room temperature was kept around 20`C. Basically he build a perfect environment for mice, what many of us would describe as Utopian place.
At day 0 he introduced in the cage 2 couples (2 Males +2 Females) of healthy and genetically perfect mice. After 104 days of adaptation period where they just were getting familiar with the environment, the mice started to mate and reproduce. The conditions were so good that the population was doubling every 55 days!..
This “born explosion” continued up to the day 315, when the population was around 620 exemplars. Despite there was still plenty of space, water and food, the mice started to feel the effect of overpopulation and some behavior anomalies started to emerge. The new born found them-self in a place where the social roles were all already taken, and there was no need for more mice… All the roles in society were constantly threaten by others. The constant fight for territory and females lead the alpha males to abandon their roles… The society started to crack and the male became really aggressive forming groups that attacked females and newborn. Mostly of them become also pan-sexual.
In same area, mortality rate for newborn rised to 96% with episodes of cannibalism (despite plenty of water and food available!). Three groups emerged:
1. The refused one, that tried to live their life in the center of the cage, with frequent episode of violence, cannibalism and pan-sexuality.
2. The females: left without male protection, they started to cluster and find refugee on the highest level nests. Without male protection, the stress level was so high, that they soon started to kill their own child.
3. The third group was called the “beautiful one” and it was mainly composed by males. They were not getting involved in any fight (this is the reason of their name) or any social role, nor were interested in reproduction or any other social activity.They were selfish, and their only day task was to eat and sleep. From time to time were mating within each other.
For the next 250 days the grow rate of the colony consistently slowed down. At day 560 the population peaked around 2200 mice. Around that time no-one of the newborn was surviving. The population started to rapidly decline and got completely extinct within the next couple of years.
Calhoun tried to take 4 mice out of the colony to a new empty cage, to make them start a new colony without success… The mice that live there were psychologically broke and unable to mate or to reproduce anymore: a psychological death that preceded the inevitable physical death.
The reason behind the extinction of the colony was to be found on the filling up all the social role. The fight for social role between new members and existing mice became so harsh that destroyed both the parties and at the end, destroyed also the underlying society.
Now a curiosity about the name.. Universe25 had such name because it was the twenty-fifth experiment of this type. All the previous experiment lead to the same result. Similar experiments have also repeated with other animals such as rats, again with the same result.
Calhoun also said something about people: he believed that independently from how much complex our society is, when the population will overtake the available social roles, similar behavior will emerge…
Well but, despite what Calhoun believed, luckily we are smarter than mice and such “Behavioral Sink” (that the official name) will never happen to humans.. Right? If we compare our current society we don’t see any of those effects on the population, right?
Or maybe not…