Milgram held that organizational roles suspend conscience’s check on impulses

Evidence

From an evolutionary standpoint each autonomously functioning element must be regulated against the unrestrained pursuit of appetites, of which the individual element is the chief beneficiary. The superego, conscience, or some similar mechanism that pits moral ideals against the uncontrolled expression of impulses fulfills this function. However, in the organizational mode, it is crucial for the operation of the system that these inhibitory mechanisms do not significantly conflict with directions from higher-level components. Therefore when the individual is working on his own, conscience is brought into play. But when he functions in an organizational model, directions that come from the higher level component are not assessed against the internal standards of moral judgment. Only impulses generated within the individual, in the autonomous mode, are so checked and regulated. — John T. Jost and Jim Sidanius, Political Psychology, 3927