Common Performance Review Biases: How to Spot and Counter Them - The Pragmatic Engineer

Watch this article as a short video on my YouTube channel. This article is thoughts from the Performance Reviews chapter of The Software Engineer's Guidebook I'm writing - subscribe to get notified when the book is published.

I've done dozens of performance reviews while I was an engineering manager at Uber. One thing I learned early on is just how many unconscious biases I had. This revelation came when I attended my first unconscious bias training at the company. As we went through biases, I caught myself thinking, "wow, I did that. Yep, that as well. Yes, that's me."

It's not just me. Biases - disproportionately favoring people and things we find familiar and the other way around - are ingrained in people from an early age. Just watch this two-minute video about five-year-olds and gender biases that develops thanks to our surrounding environment.

This article summarizes the 8 common biases I've observed in performance reviews and how you - as someone receiving this review - can counter them. Most articles I write are specific to software engineers and engineering managers. However, this topic is probably just as applicable across any company.

If you are a manager, this piece can be a reminder on what biases to watch out for. While it's great for people to have the toolset to spot and "counter" biases, good managers should consciously reduce biases in any performance review. This starts by being aware of these, calibrating reviews, and sharing with peers or your own managers, asking for their feedback if they see you being biased in certain directions.

Disclaimer: use all advice below with good judgment. You'll probably get better advice from asking your mentors and peers on specific situations: nothing beats a good support network.

How Specific Feedback are You Getting?

You're getting your performance review. Your manager is giving you feedback that you might agree, or not agree with. Pay attention to one thing: are you getting generic or specific feedback?

Specific feedback is concrete. It might follow the pattern of OFNR (Observation, Feeling, Need, Request - a great summary of this approach by Charles-Axel Dein here) or a tailored version of the STAR model (Situation, Task, Action, Result: here's the situation you were in, what your task was, what you were expected to do, what you did and the result). The point is your manager talks specifics. They mention a situation or a specific event. They talk about what they saw or heard. They tell you what they suggest you could have done differently or different output you could have achieved.

When you get specific feedback, you can have a proper conversation. Perhaps your manager missed part of the context. Perhaps they misinterpreted something. Or maybe you feel they are right. Either way, you both know what you are talking about: and this makes for generally healthy exchanges.

Generic feedback is the opposite. When your manager says, "your work is often lower quality than what it should be" or "you're overly "cautious, you end up scratching your head. Are they speculating? Based on what are they saying this? This feedback is frustrating to hear because it's so hard to pin down. It's hard to accept it, and it's even harder to challenge it.

When you notice generic feedback, aim to turn it into something specific. Ask for examples where they deducted this from. Use paraphrasing of sharing what you understood from the feedback, and ask for examples. Here's a good read to understand paraphrasing from engineering leader Padmini Pyapali.

For example, to paraphrase the generic feedback "your work is often lower quality than it should be", you could respond by paraphrasing, "So what I understand you're saying is my work frequently results in bugs, correct?" - and this will take the conversation forward. When you confirm what your manager is thinking, ask for specifics: and tell them you need specifics to digest the feedback.

Speculative feedback is when your manager tells you things that you could do or could have done, often without much specifics. "You could have done more coding" or "you could collaborate more with the team" are both this kind of feedback.

Speculative feedback is often a lazy form of feedback. As a manager, I stopped myself from giving this type of feedback without specifics, unless it was for people above expectations, and I was highlighting stretch opportunities. It's lazy because it is usually not specific, and it often doesn't even reflect on what you've been doing. As a manager with many reports, it can also be a real time saver with performance reviews to give similar speculative feedback to people.

When you get speculative feedback, challenge why your manager is saying this. What action or behavior prompts this? What situation would they recommend this in?

Make a note of what type of feedback your manager gives you - and push back on generic and generic+speculative feedback, regardless of any bias you might be suspecting. Quality performance feedback is specific, and it is fair game for you to ask for this from your manager if they haven't prepared the feedback like this. Let's jump into spotting biases and my advice on how to counter them with this out of the way.


The 8 most common biases I've observed in performance reviews

1. Recency Bias

By far, the most common bias I've observed (and it's one I'm naturally drawn to being biased towards). At many places, performance reviews are every 6 or 12 months. Managers will weigh the most recent events in the past one or two months a lot more than the events before.

How to spot it: when your manager talks about your achievements or mentions examples: if you only hear of things in the recent past, this bias might be in play.

How it can work in your favor: if you delivered something outstanding recently, and your manager refers to this frequently in your review, this might result in a more positive review. Being aware of this bias is also why it usually "doesn't hurt" to focus more than a month or two before performance reviews.

How to counter it: the best way to do so is before the review. Keep a log of the work you do, and send over a self-review or work log to your manager before performance reviews start.

On the review, ask your manager to talk through what work they have observed you do. This is to confirm they are taking older work into account. If they miss things: pull up your document and tell them what is missing. If they give you feedback where you feel the past examples would be helpful, tell them so.

Notes for managers:

  1. Make it a habit to start the performance review by listing all the work and achievements of the individual in person: both when you are writing it and when you are delivering it.
  2. Ask them if you missed something, even if it was a long time ago.
  3. If you did miss things a while back, be aware that you might have biased for recency.

2. Strictness Bias

This bias happens when your manager is overly strict in their evaluation with a few people - this could include you. If there are expectations for the job, they'll often apply them to the T. They'll hold you to higher standards than others - though you might not know this unless you compare performance reviews with your team members.

How to spot it: this is one of the trickier ones to notice and put the finger on. If you feel that your manager is nitpicking or holding an unusually high bar, they might be biased with strictness.

How it can work in your favor: in the short term, it doesn't. On the long term, if you embrace the "strictness" and work to prove your manager wrong, you might grow faster. I had a manager who I felt was overly strict on me on coding quality, and I doubled down on reading books, familiarizing myself with best practices, which made a better developer, looking back. It's not how I felt at the time, though: I felt mistreated.

How to counter it: when the feedback is generic or speculative, ask for specifics to talk about. However, the strictness bias often comes with specifics.

My best advice is to "embrace" it. Tell your manager that you didn't understand this is where the bar was. Since this was the case, you probably still don't understand where it is. Would they be willing to help with your commitment that you're putting energy into growing?

Strictness bias often comes from your manager, not knowing too much about your work. So change this. Have regular catchups where you talk about your work, the changes you made (taking advice) and ask for their feedback. Rinse and repeat.

Managers get (usually) tend to get fond of people who take action on their feedback. It's counterintuitive, but try to spend more time with a manager who might have a strictness bias, ask for more frequent feedback, and keep a log of this feedback and the changes you're making.

This bias can be hard and exhausting to counter. If the feedback is generic, you can counter it by asking for specifics. However, one of the best ways I've found to counter this type of bias is to get your manager "on your side" for the coming period.

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3. Leniency Bias

The opposite of the strictness bias: your manager going overly "easy" on you.

How to spot it: you probably won't go "hunting" for this one :)

How it can work in your favor: you'll get a better and nicer review!

How to counter it: this is not one you'd want to counter, even if you notice it particularly.

A note for managers: calibrating your feedback is key to spotting strictness and leniency biases. Compare notes. Are you overly strict on certain people - especially ones not similar to you or ones you have negative feelings for? Are you too lenient with people you really like?

4. Horns Bias

This bias refers to one negative attribute or behavior being generalized in the mind of the manager, unfairly pulling the whole performance review down.

How to spot it: if your manager starts by giving strong negative feedback on a certain area, or for a certain event, and keeps bringing this one thing up at other places, you can suspect horns bias. It can also be the case when your manager seems to point a lot of negative emphasis on something you didn't think was that big of a deal.

For software engineers, an area that could cause horns bias includes the manager perceiving their direct to have "messed up" an important project or one or two examples of negative feedback from someone the manager trusts. Of course, there are far more that could result in this bias.

How it can work in your favor: this bias can only work against you.

How to counter it: to counter this bias, you first need to identify what this big, negative trait or behavior might be. In your performance review, you should hear something repeating again and again. Once you figured out what this thing could be, poke at it.

Ask: "if {the specific thing} did not happen, how would you rate {different area that had generic feedback}"?

If your manager says it wouldn't make a difference, challenge them on why this is the case. If they say they would rate it neutral, dig into if the "negative" example was a lone incident or a pattern. Ask for more examples of the original "negative" incident. If it was only a one-off, you could remind your manager that it feels like horns bias to have a one-off incident impact your whole performance review outside of just one area.

5. Halo Bias

This is the opposite of the horns bias. It's when a single positive event/attribute pulls your whole review up, across the board.

The most common halo bias happens when someone on the team goes over and beyond to "save" the most critical project. Managers tend to be grateful to this person and recognize the major positive impact they had. As a manager, I can share how it's hard not to fall into the trap of the halo bias and not go "easier" on this person in other areas. I've personally been guilty of this bias.

How to spot it: you'll get an overly positive review from your manager after you've done something really great for the team. The review might have zero criticism and little to no areas for further improvement.

How it can work in your favor: you get a great review! However, you might not get feedback on some of your growth areas.

How to counter it: there's little need to do so. However, you can always ask your manager what the top area for further improvement that they can see is.

A note for managers: be careful with halo and horns biases. It's very easy to step into these: I can confirm, as I've been guilty of both. Counter the halo bias by having improvement areas for everyone, no matter how good they are doing. Counter the horns bias by making sure one-offs and single traits don't cloud a whole review. Comparing reviews with each other and asking for a second pair of eyes can also be helpful to avoid these biases.

6. Similarity Bias

This one is engrained in nature: animals flock to those who look similar to them. Similarly, humans tend to favor other humans who look or feel similar to them. This can result in leniency and halo biases for those a manager "feels" closer with, and strictness and horns biases for those who they not.

How to spot it: you'll probably experience a mix of strictness and horns bias from a manager you don't "feel" that close to. If you and your manager have different personalities, gender, race, cultural background, and other "major" differences, those biases might have to do with the manager having a similarity bias.

How it can work in your favor: you could be on the "good" side of the bias if your manager "feels" similar to you. You might experience leniency and halo bias in this case.

How to counter it: this is a tough one to work with. Even if you recognize this bias, you can't just tell your manager they have similarity bias.

The best advice I have is similar to working through the strictness bias. As counterintuitive it is, spend more time with your manager. Get to know them. Share your background. Share a lot more about your work and how you approach things. Ask for frequent feedback on your performance. Set goals together.

However well you mean, if your manager does not recognize this bias, you might feel unfairly treated. If this persists, the solution might be to find a new manager or team.

A note for managers: there's little your direct can do if you leave similarity bias unchecked, beyond quit working for you. It's on you to reduce the likelihood of this happening. Double-check your language and attitude with people who are not similar to you on the team. Spend time to understand their background and way of working.

Diverse teams are known to outperform homogenous teams. To build a diverse team, you need to keep a conscious eye on similarity bias.

7. Central Tendency Bias

Managers have a tendency to not want to differentiate people significantly within the team. If you ask a manager to rate people on their team from 1 to 5, with no constraints, many managers would be tempted to give everyone a 3. Differentiating feels to go against the spirit of the team.

As a fun fact: this bias is one of the main reasons that several companies have introduced forced performance ratings when only a certain % of people can be rated in the middle. For companies that have this rating, usually, 10% need to be above average, and 20% need to be above average.

Even in companies with no forced performance ratings, HR professionals vary this bias, and they will "push" managers to differentiate between average, low, and higher performers.

How to spot it: if you have a performance review process where you get a rating or number for multiple areas, and all of these areas are average or the middle, then your manager might be leaning towards a central tendency bias.

How it can work in your favor: if you might have been a bit under expectations for an area or two, perhaps this bias "helped you". It can hurt you just as much if you were actually above expectations, and this leaning towards the average pulled you down.

How to counter it: when you are getting a "very average" review, push your manager to identify a strength and a growth area. Ask them: "if you can point out one area where I stand out, which one would that be? Why do you think so? Given this is a strength, would you say it's above the expectation? If not, what am I missing? If it is, what is missing for this competency to be rated as above average?"

Similarly, ask for a growth area - of course, there's no need to advocate for a lower rating there! Still, feedback is valuable, and you should get better feedback than just "average".

8. The Contrasting Bias

Managers will naturally compare people with each other - in their heads. However, a performance review should be more objective. It shouldn't be about how you compare to teammate one or two, but how you are doing against expectations. Too much comparing can skew the feedback, and you might get a review that is relative to others, not to what the objective bar is.

How to spot it: if your manager keeps comparing you to specific people on the team or frequently compares you to "others", this bias might be at play.

How it can work in your favor: when you are compared as a good example, this bias can put you in a more positive light. However, you're more likely to be compared to others in a not positive setting.

How to counter it: when your manager compares you to someone, ask them if they can describe the same thing without referring to that specific person. When they compare you to "others", ask who those "others" are. Team members? If so, which team members?

Contrasting bias often happens when there are no clear role expectations defined. If this is the case, you could get a bit more proactive and ask your manager to describe someone who is an average or above-average performer: but talking about traits and behaviors, not names.

As your manager describes, take notes. You're now doing the work they should have done: collecting what the expectation is. When they are done, it's your turn to shape this expectation. Ask about the strengths of yours. For example, if you have strong documentation skills, ask, "do you think the expectation at this level would involve strong documentation skills?" If they say yes, you can add this to the list, and note how this is a strength of yours. If they say no, you can push a bit more and find out why not. Perhaps that's for the next level?

If you are on the wrong end of the contrasting bias, and there are no clear expectations for the role, it's in your interest to clarify these. You can also tell your manager that it would be very helpful to have this, as being compared to other people all the time isn't exactly fair.

A note for managers: contrasting is such a natural thing to do: and you absolutely should forget using this tool. It's another form of very lazy feedback that can only hurt people in the short- and long-term. If you have a career ladder and expectations per level, calibrate your feedback against that. And if you don't have one: time to put one together - here's a book that details how you can go about this as an engineering manager.

Focus on the Feedback You Can Grow From

Every performance review can carry several biases, and it's helpful if you can spot them and blunt their edge. At the same time, biases or not, your manager's goal should be to help you grow professionally through the feedback they deliver.

Don't be a pushover with unfair feedback, and challenge your manager for specific feedback when overly generic with their message.

Try to find the parts of the feedback that are actionable and ones that you want to get better at. When you disagree with the feedback, try paraphrasing over getting immediately defensive. Sometimes the best feedback can be painful but necessary to hear. Good luck with the review!

You can watch this article as a video on my YouTube channel: performance reviews - how to spot and counter common biases.