Institutional memory is a collective set of facts, concepts, experiences and knowledge held by a group of people.
Conversely, institutional memory may be ingrained to the point that it becomes hard to challenge, even the conditions that caused it to arise have changed.
An example of this would be an organization continuing to submit a form, even after the law requiring that document has been repealed, for fear of legal consequences that no longer exist.
Alternatively, the evolution of ideas in Marxist theory is that the mechanism whereby knowledge and wisdom are passed down through the generations is subject to economic determinism.
Progress to higher echelons requires assimilation of this, and when outsiders enter at a high level, effectiveness tends to deteriorate if this morale is unjustly ignored.