I put aside for the time being major horrors such as Nazi Germany or English soccer crowds on the rampage to begin with a minor example of errant group mind. In my home town in November 2012 the local newspaper brought to attention that one of its university colleges subjects its new members to humiliating initiation rites. Surprise! A young woman forced to drink dog food, sour milk, alcohol, Tabasco sauce and shampoo survived. I wonder whether the drink included faeces, which students smear through the college during their bouts of heavy drinking. The college rector had tried futilely for years to change the group mind, thwarted from effective action by its establishment.
The newspaper quoted a student. “The peer pressure is enormous and impossible to explain. I was forced to do things that I would never want to speak about again … Every single day I was witness to a vindictive culture that propagates racist, homophobic and sexist conduct among the students.” I suggest that only the common failure to take into account the tyranny of the group mind makes it “impossible to explain”.
Over more than 60 years of distant awareness I can say that the group mind of this college kept its form. It helped to shape its establishment, which strives to keep its traditions. As a year representative in 1952 I remonstrated with a group from the college for disrupting  lectures. Beyond the hoots and catcalls they responded with silent malice. Not until years later did I learn that they had put paper into the tubes of my stethoscope,  hampering my ability to detect the signs on which  examiners made their judgements about who will graduate and patients depended for recognition of their pneumonia or heart failure. Their disregard for the possible consequences illustrates the nature of their tradition. A student I knew died in the college after inhaling  nitrous oxide, which the students stole from the local hospital. They had done so regularly without fuss. All was hushed up by its establishment. Even the parents of the young man did not remonstrate. In contrast, the young woman who survived her initiation lived to tell the tale. The people of my state will be interested to see whether this group mind will alter, but will anybody try to learn from it how to transform the group mind gone wrong?
