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Groundbreaking studies in the 1950s found mice turn disturbingly violent and cannibalistic when subjected to overcrowding.

Scientist John B. Calhoun created mouse utopias in which the rodents had all the food, water and bedding they required.

But after several generations, the booming population descended into chaos with male mice becoming savagely violent and females failing to nurture their young.

The subsequent generation became known as the "beautiful ones" – non-violent but interested in little else other than grooming themselves.

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These mice were unable to interact socially with one another and had no interest in sex, leading to the extinction of the population.

Tragically, even when this traumatised generation was removed from the stress of their surroundings they still did not recover and lived out their days in solitude, fixated on grooming.

The professor saw the doomed mice as a metaphor for the fate of mankind and called the societal breakdown a "second death" in reference to the Biblical book of Revelation 2:11.

The terrifying study led to Prof Calhoun advising NASA and federal prisons.

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But will overcrowding really result in destruction and death for humans?

Shockingly, the most recent generation of teenagers - dubbed Generation Z - were found to be less interested in sex than any other generation from 1976 onward, staying indoors, scrolling through social media and taking selfies.

Psychologists Jean Twenge and Heejung Park published their findings in the journal Child Development.

But Prof Twenge puts the phenomenon down to smartphones and technology.

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Although with a global population of 7.2 billion, expected to swell by another 1 billion in just 12 years, there is no telling what future generations of humans will have to face as living space becomes increasingly cramped.

And in densely-populated Japan, a disturbing trend dubbed "hikikomori" has gripped the younger generation, with an estimated half a million Japanese youth living as social recluses.

The Japanese government defines hikikomori as people who haven't left their homes or interacted with others for six months or more.

But again, a link to overcrowding wasn't made.

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In a review of Tragedy in Mouse Utopia by JR Vallentyne, economist Max Kummerow Ph.D said Calhoun's work was "food for thought".

He said: "The use of animal models is problematic, of course, because results may differ between the animal model and humans.

"We obviously tolerate living in cities of 20 million or more of us.

"But I do think this book offers important food for thought. Humans are violent. We have nuclear weapons."