·Psychology & Behavior
Section 1
The Core Idea
In 1968, Robert Rosenthal and Lenore Jacobson ran an experiment at a San Francisco elementary school that would reshape how psychologists thought about expectation and performance. They told teachers that certain students had been identified by a special test as "intellectual bloomers" — kids about to experience a dramatic surge in academic ability. The test was fake. The students were randomly selected. But by the end of the year, the "bloomers" showed significantly higher IQ gains than their peers. Teachers had unconsciously given these students more attention, more challenging material, warmer feedback, and more patience. The expectation created the reality. Rosenthal and Jacobson called it the
Pygmalion Effect.
The Golem Effect is its dark twin.
Named after the golem of Jewish folklore — a creature brought to life by a rabbi but constrained by its maker's limited expectations of what it could become — the Golem Effect describes what happens when low expectations create low performance. Not through incompetence. Not through lack of talent. Through the systematic withdrawal of the conditions that performance requires. When a manager expects someone to fail, they give less feedback, fewer growth opportunities, less autonomy, less access to resources, less benefit of the doubt. The employee, deprived of the raw materials of development, underperforms. The manager sees the underperformance and thinks: "I knew it." The prophecy fulfils itself not because it was accurate but because it was acted upon.
The mechanism is brutal in its precision. Rosenthal's subsequent research documented the four-factor framework through which expectations transmit: climate (warmth, attention, eye contact), input (more challenging material for high-expectation subjects), output (more opportunities to respond and contribute), and feedback (more specific, more constructive, more frequent). When expectations are high, all four factors increase. When expectations are low, all four decrease — often unconsciously. The manager who has labelled an employee "not leadership material" stops inviting them to strategic meetings. The manager who has decided a team is "B-level" allocates fewer resources and less executive attention. The manager who has concluded a new hire "probably won't work out" gives less onboarding support and checks in less frequently. Each withdrawal is individually small. Collectively, they construct an environment where underperformance is the rational adaptive response.
The Israeli Defense Forces provided one of the most rigorous demonstrations. In a 1982 study, Dov Eden randomly assigned leadership-expectation labels to incoming trainees in a military course. Instructors were told that certain trainees had been identified as having "high command potential" based on psychological assessments. The assessments were fabricated. The "high potential" trainees outperformed their peers significantly — not because of innate ability but because the instructors taught them differently. They received sharper corrections, more individual coaching, and more demanding exercises. The trainees labelled average received average instruction and produced average results. The expectation did not predict performance. It manufactured it.
In corporate environments, the Golem Effect operates at every level. A CEO tells the board that the European division is "non-strategic." Resource allocation shifts toward the "strategic" divisions. The best talent transfers out of Europe because career advancement follows resources. The European leadership team, stripped of investment and top performers, delivers declining results. The CEO reviews the numbers and says, "This is why we deprioritised Europe." The circularity is invisible to everyone inside it. The label created the conditions that validated the label.
Startup culture is especially fertile ground. A founder who tells the team "we're probably not going to make it" is not being honest. They are triggering the Golem Effect at organisational scale. Top performers start interviewing elsewhere. Middle performers reduce effort because the expected outcome no longer justifies personal sacrifice. The founder's prediction becomes a coordination signal: disengage. The startup's decline accelerates — not because the market was unwinnable but because the founder's expectation withdrew the commitment that winning required.
The most insidious feature: the Golem Effect operates below conscious awareness. Managers do not decide to withdraw resources from low-expectation employees. They simply allocate more to high-expectation ones. Teachers do not choose to call on certain students less. They naturally gravitate toward the students who "seem" most engaged — the ones they have already labelled as high-potential. The asymmetry feels like merit-based allocation. It is expectation-based allocation wearing the mask of objectivity. The Golem Effect does not require malice. It requires only assumptions — and humans carry assumptions into every interaction. The antidote: assume competence until proven otherwise.