During the decline, a number of strange behaviors were noted.
Females became more aggressive and male-like. They kicked their young out of the nest before they learned proper social behaviors. Males became disinterested in having sex. Females had to pressure the males for sex. Some homosexual behavior was witnessed.
Mice in the colony ceased to engage in normal, complex mice behaviors. They started clustering together into large groups in areas designed to hold smaller numbers. They would randomly attack each other. Cannibalism began, despite the unlimited food availability.
The most interesting were male effeminate mice who isolated themselves from the rest of the group and never had sex. They spent their entire day standing with others like them, eating, drinking, sleeping, and grooming themselves and each other. Calhoun described them as autistic creatures capable of only the most basic physiological behaviors. He called these the “Beautiful Ones” as their grooming led to clean, attractive, smooth fur coats.
When the social bonds of the colony ceased to function, Calhoun noted:
“Their spirit has died (the first death). They are no longer capable of executing the more complex behaviors compatible with species survival. The species in such settings die”
At the end of the experiment all that were left were the Beautiful Ones, females not interested in males, and social outcasts who did not perform normal mouse behaviors.
The Mouse Utopia experiments raise interesting questions about human populations. Prior to the industrial revolution, Western child mortality was around 40%, but this is now at 1%. Like Mouse Utopia, human populations have broken free of Darwinian selection. Humanity’s population pyramids are inverting. This is most advanced in Japan:
Japan’s population is falling. Women are not interested in children. Men have lost interest in sex. Many don’t even bother to masturbate. Evolutionary maladaptive behaviors are entrenched. There is no end in sight. Other countries, like China, are following close behind. In America immigrants are replacing the native population, masking the same trends. Across the world fertility rates continue to decline.
What is happening to humanity?
Due to modern innovations in genetics, researchers have been able to identify a genetic mutation for autistic behavior (like the Beautiful Ones) in rodents to NLGN3 (paper 1; paper 2). Researcher Michael Woodley and his colleagues ran an experiment where sufficient numbers of captive-bred NLGN3 knockout mice were mixed with a population of wild mice. As in the Mouse Utopia experiment, the genetically-damaged mice caused social damage to the entire population. However, if the defective ones were removed, then the colony would begin to recover within as little as a week.
To explain these results, Michael Woodley formulated a general theory of Social Epistasis Amplification. The notion is that genetic mutations of a few can still have deleterious effect on the population of social species as a whole through genetic interactions at the social level (i.e. ‘interorganismal gene-gene interactions’).
Human populations are experiencing the effects of social epistasis. Feminism is one example. Feminists, who often have high mutational load, routinely promote genetically maladaptive behaviors (e.g. the birth control pill; abortion; forced assent of homosexuality and transgender issues; delayed marriage) on those with low mutational load. Doing what they suggests literally harms society, even as it is declared virtuous. Moreover, it is not sufficient to reject feminism: nearly everyone is influenced. MGTOW is one example of resulting maladaptive behavior.
Future parts of this series will explore how we got to this point and expand upon these concepts in greater detail. The series continues in part 2.
 And, unlike the mice, humans do not have unlimited resources.
 This bears similarity to the social contagion concept.
 The “Beautiful Ones” were the mice analog of MGTOW: socially isolated and asexual. In Mouse Utopia, mice going their own way ended up destroying the colony.
 The citation previously at a link here was censored by YouTube. Inconvenient scientific inquiry is no longer permitted.