How to Avoid Bias in Performance Reviews

Kim Porter

For some leaders, performance-review season is a dreaded time of year. It takes a lot of effort to evaluate every worker’s performance and suss out their recent strengths and weaknesses. 

Another layer of difficulty? It’s hard to stay objective when writing those reviews. Research shows that managers tend to exhibit bias in performance evaluations, which might ultimately prevent them from fully tapping into their team’s capabilities. 

But there are ways to make your reviews more bias-free. Step one is just being aware of the problem—and now you’ve got that taken care of. Your next steps are understanding common types of biases, learning how to create a bias-free process, and training your managers on how to use that process. 

Why is avoiding bias in reviews important?

When biases take over, you’re no longer evaluating how the employee completes their job. Instead, you’re considering factors beyond their performance, like their personality traits or how they make you feel. Maybe you’re friends with an employee and want to see them excel, so you unintentionally write them a great review (and forget about the times they stumbled). 

Research hasn’t shown that any particular type of person is more at risk of bias, so it might be safe to assume you exhibit some form of it every now and then.

And because biases are errors in judgment, letting them guide you can lead to inaccurate performance reviews. A flawed review—whether positive or negative—could steer an employee in the wrong direction and affect their future at the company. Fairly rating each employee is in your best interest because it could help you drive better business results. It may also contribute to diversity in leadership—if positive and well-balanced reviews lead to promotions—and potentially help close the wage gap. Employees will also receive better guidance on how to improve, which may boost morale. 

8 performance-review biases to identify now 

To be fair and objective, it’s important to base the evaluation on the employee’s job-related behavior. Here are some of the most common biases managers might encounter when evaluating their employees: 

Leniency bias

Leniency bias occurs when managers give everyone on the team favorable ratings, and disproportionately leave out information about where there’s room for improvement. This might happen if a manager wants to boost morale, motivate an underachieving employee, or hurry through a stack of reviews by a certain date. But giving positive reviews across the board can make it hard to distinguish between the truly top-performing employees.

Severity bias

Your reviews could lean the other way, too, if you tend to dole out poor scores to everyone regardless of their actual performance. You might hope that a poor review will motivate an underachieving employee or undermine an arrogant worker—but it could backfire if it has the opposite effect on the entire team instead.

Similar-to-me bias

We tend to value people who are most like us, so a manager may give the best reviews to employees she relates to most. But when managers ignore the strengths of people who are different, they may severely limit opportunities for other employees, alienate team members, and even affect the diversity of the team. Employees of color may feel they need to employ “comfort strategies” for white people in order to be promoted. And on the flip side, managers of color or female managers may feel pressured to evaluate their own group using tougher criteria to prove there’s no bias. 

Primacy bias

Have you ever let a first impression affect how you feel about someone or how you treat them? With the primacy bias, a manager learns information about an employee early on and lets it guide their evaluation. For instance, maybe your employee landed a big client on the first day at the job, and you don’t realize they haven’t done much since then. But when you emphasize a first impression, you ignore the employee’s later performance—whether it’s good or bad.  

Horns/halo effect bias

The horns/halo effect happens when one good or bad trait overshadows others. On the halo side, you might give an employee an excellent review if they have a strong sales record, for instance, even if they need to work on communicating better with co-workers. And on the horns side, you might give a negative review to someone who’s always late but generally does good work. Both types of bias will skew your reviews.

Recency bias

With recency bias, a manager bases an evaluation on something the employee did within the last few days or weeks instead of the entire evaluation period. Businesses might be vulnerable to this bias if they perform annual reviews. While recent performance might indicate where the employee is headed, a review is more complete when it encompasses the entire evaluation period.

Contrast bias

If you tend to review an employee in the context of the entire team—essentially ranking them — that’s contrast bias. In most circumstances, employees need not be ranked in a lineup or pitted against each other. Instead, they should be reviewed against an established company standard that evaluates each employee’s performance. 

Gender bias

According to research by Harvard Business Review, performance reviewers often use different words to describe men and women’s capabilities. Women tend to receive short reviews with vague feedback that lack details for what they’ve done well and how they can advance. These reviews usually focus on communication skills and criticize female employees for being too aggressive. Men, on the other hand, typically receive longer reviews that focus on their technical skills. They’re typically criticized for being too “soft.” Additionally, managers may exhibit bias toward employees who are mothers, focusing on their perceived priorities rather than their performance. 

How to structure reviews to avoid bias

Before setting up your review structure, it’s a good idea to go over the biases with your management team so they know what to look for (and avoid). Discuss why it’s important to have accurate and objective reviews and what might get in the way. After managers write their first set of reviews, consider looking over them—or asking human resources to—and checking for biases

Gather information over time 

It’s nearly impossible to remember every employee’s moves over the course of a quarter or a year, so get into the habit of taking notes. Write down specific details on your employees’ achievements, setbacks, and notes on how they can improve. At the end of the review period, you should have plenty of information to write a fair review.

Establish a methodology

It’s also important to figure out how you’ll structure the reviews and use that method consistently. This can help ensure the assessments are fair across the team. For instance, you might ask your employees to send you a list of their goals, hold casual quarterly reviews that feed into the official annual review, and check performance metrics like sales records or customer feedback. Coupled with your notes, you’ll have a lot of evidence on whether the employee met expectations and achieved their goals. 

Create more specific prompts

When managers have to answer open-ended questions without much guidance—known as the “open box” approach—they tend to lean on stereotypes about gender and race instead of assessing an individual. So for each prompt that’s listed on the review, include a list of clear, specific criteria. For instance, this prompt is vague: “Describe how the employee’s performance met your expectations.” A more specific prompt would be: “List three ways the employee contributed to [X team achievement] this year.” 

Write down clear goals

Teams tend to perform better when the company sets clear and ambitious goals, and employees align their own work goals with company standards. Ask your employees to send you their goals at the beginning of the quarter or year, so you can track their progress more effectively. This can also reduce recency bias. Research suggests goals should be “FAST”

  • Frequently discussed
  • Ambitious
  • Measured by Specific metrics and milestones
  • Transparent

Check for consistency and bias

Even if you’ve followed your new criteria and used checklists, you may fall into some patterns. So once you’re done with the reviews, read through all of them and look for consistency. Have you objectively rated each employee, or do you notice any concerning trends? If you’re in a negative mindset, for instance, you may have given unfairly negative evaluations. By looking for these patterns, you may be able to reduce bias.

Kim Porter Kim Porter covers personal finance topics for AARP The Magazine, Bankrate, U.S. News & World Report, Reviewed, Credit Karma, and more. When she’s not writing, you can find her training for her next race, reading, or planning her next big trip. Twitter | LinkedIn
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