Another strand in the documentary is the work of R.D. Laing, whose work in psychiatry led him to model familial interactions using game theory. His conclusion was that humans are inherently selfish and shrewd and spontaneously generate stratagems during everyday interactions. Laing's theories became more developed when he concluded that some forms of mental illness were merely artificial labels, used by the state to suppress individual suffering. This belief became a staple tenet of counter-culture in the 1960s. Reference is made to an experiment run by one of Laing's students, David Rosenhan, in which bogus patients, self-presenting at a number of American psychiatric institutions, were falsely diagnosed as having mental disorders, while institutions, informed that they were to receive bogus patients, misidentified genuine patients as imposters. The results of the experiment were a disaster for American psychiatry, because they destroyed the idea that psychiatrists were a privileged elite that was genuinely able to diagnose, and therefore treat, mental illness.