# Peter Principle

## Statement
The Peter Principle holds that in any hierarchical organization, employees are promoted based on competence in their current role until they reach a position where they are no longer competent, at which point they remain. Over time, every role tends to be occupied by someone who is marginally unqualified for it.

## Origin
Laurence J. Peter and Raymond Hull articulated this principle in their 1969 book "The Peter Principle," using satire to expose a structural flaw in promotion-based advancement systems. Peter, a Canadian educational psychologist, observed that schools promoted excellent teachers into administrative roles where many struggled, not because they were incompetent people but because teaching and administration require fundamentally different abilities. The book resonated far beyond education, becoming a staple of management literature and organizational theory.

## Software Implications
The software industry provides especially clear examples because the skill gap between technical roles and management roles is wide. A staff engineer who debugs distributed systems with precision and writes elegant abstractions may lack the patience, empathy, and communication skills needed to manage a team of ten. Promoted to engineering manager, this person now spends their days in one-on-ones, hiring loops, and performance reviews, tasks for which they have neither training nor aptitude. The team loses a brilliant engineer and gains a mediocre manager.

The principle also operates within the technical ladder. A strong junior developer who writes clean, well-tested code is promoted to mid-level and given design responsibilities. If they struggle with system-level thinking, they plateau at mid-level. A mid-level engineer who designs good services is promoted to senior and expected to drive cross-team architectural decisions, which require political navigation and persuasion skills that design skill alone does not confer.

The cumulative effect is that organizations gradually fill leadership positions with people who have reached their incompetence ceiling. These individuals then make the promotion decisions for the layer below, perpetuating the cycle. The result is an organization where the most competent people occupy the positions where they are least effective.

## Practical Guidance
- Assess candidates for promotion based on demonstrated competence in the target role, not just excellence in their current role.
- Create robust individual-contributor tracks so that technical experts can advance in scope and compensation without being forced into management.
- Offer trial periods or acting roles that let people experience the responsibilities of a new level before making the promotion permanent.
- Allow and destigmatize lateral or downward moves when someone discovers that a new role does not suit them.

## Common Misreadings
The Peter Principle does not claim that all managers are incompetent, only that promotion systems based solely on current-role performance systematically place some people in roles where they cannot succeed. Many people do grow into new responsibilities, and many managers are highly effective. The principle describes a systemic tendency, not an individual judgment.

Some organizations misinterpret the principle as a reason to never promote anyone, which is as damaging as over-promoting. The correct response is to change the promotion criteria, not to freeze advancement entirely.

## Interactions
The Peter Principle feeds directly into Putt's Law, because promoting a technical expert into management removes domain expertise from the practitioner layer and adds a potentially weak manager to the decision-making layer. It intersects with Price's Law by shrinking the productive core when top contributors are promoted past their effectiveness. The Dilbert Principle describes the complementary organizational failure mode where incompetence is actively channeled into management rather than being reached accidentally through promotion. Goodhart's Law explains one mechanism: organizations use past performance as a target metric for promotion eligibility, and once people know the target, they game it rather than developing genuine readiness for the next role.

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*Based on: Peter & Hull, "The Peter Principle" (William Morrow, 1969)*
