That summarization includes a video I hadn’t seen before where Calhoun explains the results in his own words and mentions the case of the Ik tribe which I didn’t know about:

> [00:01:55] at least one human group, the Ik tribe discovered in Africa by dr. Colin Turnbull (https://en.wikipedia.org/wiki/Ik_people#The_Mountain_People) has gone through a similar terrible process according to dr. Calhoun: the two conditions that they went through was that there was a decision on the then colonial government to make a wildlife preserve of this big valley which was their home as they are hunter-gatherers, they moved them up onto the mountainside and gathered together in much higher densities, they had been spread out small groups, all placed in one place and also required to engage entirely different way of life, which their social roles, the whole… everything they had learned how to do had no meaning. Under those conditions the social behavior broke down. Entirely they began living… they still live together but their activities was just directed towards themselves, everything you would think is human disappeared.