Accurately and fairly evaluating employees is a critical skill for both employers and managers. However, one of the greatest challenges in performance management is combating biases that can distort evaluations. The truth is, we all have biases, even if we are unaware of them, and these can affect how we assess employee performance.
In fact, a Harvard Business Review study found that 76% of men and 85% of women managers viewed performance evaluations as highly ambiguous and subjective. Recognizing and addressing these biases is essential to conducting performance evaluations that are accurate and fair.
Here are some of the most common biases in employee evaluations and practical tips on how to avoid them.
Central tendency bias occurs when managers rate all employees in the middle or “satisfactory” range, regardless of their actual performance. This often happens when a manager evaluates many employees and unconsciously starts giving similar scores to everyone to avoid making difficult judgments.
Example: Imagine a manager overseeing 20 employees. Instead of recognizing individual strengths and weaknesses, the manager gives nearly all of them a “satisfactory” rating. This not only demotivates top performers who aren’t recognized for their efforts but also overlooks underperformers who need improvement.
To prevent central tendency bias, focus on each employee’s individual performance and how it aligns with the expectations of their role. Collect performance data at multiple points throughout the year rather than relying on a single evaluation period.
This provides a more comprehensive view of each employee’s contributions and ensures that standout performers receive the recognition they deserve.
Central tendency also includes two subtypes of bias, a severity bias and a leniency bias.
Leniency bias occurs when a manager rates all employees too positively, while severity bias happens when the manager rates all employees too harshly. Both extremes can distort the performance review process and lead to frustration.
Example: A manager who wants to avoid conflict may give all employees high marks (leniency bias), even when some are clearly underperforming.
Conversely, a manager trying to motivate employees might rate everyone low (severity bias), hoping that tough evaluations will encourage improvement.
Unfortunately, leniency bias creates a false sense of accomplishment, while severity bias can lead to disengagement.
To counter these biases, establish clear evaluation criteria and use a consistent rating scale. If using a 5-point scale, consider eliminating the middle or neutral option, forcing managers to make a definitive judgment about performance.
By creating distinct rating categories, managers are encouraged to think critically about each employee’s achievements and areas for improvement.
Halo and horn bias occur when managers allow a single trait or characteristic of an employee to disproportionately influence the entire performance review.
Halo Bias happens when a manager gives an employee an overly positive evaluation based on one strong trait, such as their punctuality, or even unrelated factors like supporting the same sports team. This singular focus can overshadow areas where the employee may need improvement.
Horn Bias is the opposite, where a manager gives an employee a negative review based on one disliked trait or past mistake, even if the employee excels in other areas. This bias can manifest as a result of personal preferences or even unconscious discrimination, such as sexism or racism.
Why It’s Problematic: No employee is perfect, and focusing on just one aspect of their performance—whether positive or negative—means overlooking other key contributions or challenges. This can lead to unfair evaluations, with high-performing employees going unrecognized or employees being penalized for one-off issues.
To avoid halo and horn biases, managers need to adopt a structured and objective performance evaluation process. Research shows that using a consistent, well-defined decision-making process is six times more effective than relying on subjective judgments.
Evaluating employees across multiple metrics ensures that no important qualities are overlooked, and it helps uncover faulty logic, such as cherry-picking evidence to fit a preconceived conclusion.
Recency bias occurs when a manager focuses primarily on the most recent work or interactions they remember with the employee, allowing these events to overshadow their overall performance throughout the evaluation period.
For example, if an employee closed a big deal just before the review, they may receive a high rating, even if their performance was inconsistent or underwhelming earlier in the year.
Primacy bias, on the other hand, is the tendency to give more weight to an employee’s initial performance, often overlooking their more recent achievements or struggles.
A manager might continue to rely on their first impressions of an employee’s past successes or failures, regardless of their current work.
The spillover effect also plays a role here. This happens when a manager assumes that an employee’s past performance trends—whether positive or negative—are continuing without thoroughly evaluating recent work.
For instance, if an employee has consistently performed well in the past, their manager might assume they’re still doing well and neglect to carefully assess their recent contributions.
Why It’s Problematic: Both biases skew the accuracy of evaluations, leading to unfair assessments. Recency bias can result in overrating short-term successes, while primacy bias can lead to outdated assessments that don’t reflect an employee’s current abilities or efforts.
To reduce the impact of recency and primacy biases, managers need to assess performance over the entire evaluation period, not just based on recent or early impressions.
Documenting regular feedback throughout the year and reviewing an employee’s contributions at multiple intervals ensures a more balanced and fair evaluation. When employees work in teams, be sure to evaluate their contributions to get an accurate picture of their performance.
By maintaining a structured, consistent review process, managers can prevent these biases from skewing the performance appraisal and ensure that evaluations reflect an employee’s true capabilities over time
Similar-to-me bias occurs when managers give higher ratings to employees they perceive as being similar to themselves, whether in terms of interests, personality, or background.
Example: A manager who shares a hobby or alma mater with an employee might give them a better evaluation because they feel a connection, even though other employees are performing just as well, if not better.
To reduce similar-to-me bias, set specific, measurable criteria for performance evaluations. Ensure that all employees are assessed based on their achievements and contributions rather than personal connections or similarities.
Using a structured, objective review process helps maintain fairness and focus on performance rather than personal traits.
Avoiding biases in performance evaluations is essential to fostering a fair, motivating work environment. By being aware of biases like halo, horn, recency, and primacy, and implementing structured evaluation processes, managers can ensure that employee assessments are accurate and objective.
Ultimately, this leads to more informed decisions, greater employee satisfaction, and a stronger organizational culture.
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