What psychological bias may lead a manager to unfairly rate an employee based on a single incident of underperformance?

The psychological bias that may lead a manager to unfairly rate an employee based on a single incident of underperformance is the recency effect. The recency effect refers to the tendency of individuals to give more weight to recent events when evaluating performance, causing them to overlook past achievements and consistent performance. This bias can skew the assessment process and result in an unfair rating based on temporary or isolated incidents, rather than a comprehensive view of the employee's overall performance.

In contrast, the halo effect involves allowing positive traits or past successful behaviors to influence an overall assessment, which can create a biased perspective in the other direction. The contrast effect refers to how a person's evaluation can be influenced by the performance of others who are being assessed at the same time. The sunk cost fallacy pertains to decision-making where past investments influence future choices, rather than focusing on current performance. Understanding these biases is crucial for fair evaluation and effective management practices.