The author's formulations and illustrations concerning group identification are based on studies of surgical patients and wartime danger situations. He applies his hypotheses to face-to-face groups where there is a common source of external stress. Transference to the group leader, with partial regression, the establishment of dependency, infantile love and hate with overestimation of the power of the surrogate, is derived from Freud's 1922 monograph.

Janis also applies his hypotheses to delinquent behavior through a series of mechanisms based upon 'sharing the guilt', sharing of common fears, and heightened cathexis of the group which results from mourning for lost members. The same psychological processes seen in extreme form in combat groups