Measuring employee performance can be a daunting task, especially for managers who feel they lack the skill and time to evaluate the capabilities of others. The challenge of assessing work and delivering feedback is made harder by the subtle but significant biases we carry around in our heads. These cognitive traps can cloud our judgment and complicate decisions about pay and promotion.

While a number of my clients have taken positive steps towards increasing contact time between managers and their reports, they confide that the real challenge may be lurking deep inside the unconscious mind. Preventing these latent biases from creeping into the talent cycle starts with a clearer understanding of what these traps are and how to check them before it's too late. 

Common Cognitive Traps

When I ask managers about their experience rating others, they typically identify the following four cognitive traps that interfere with their better judgment: 

  • Central tendency bias: Statistically speaking, a measure of central tendency refers to a typical value of probability -- how likely something is to occur over time. When it comes to measuring performance, it refers more generally to the tendency of raters to evaluate others close to the average. Whether it's their lack of performance data or the fear of assigning a low rating, managers may choose to falsely lump people in the middle. 
  • Recency bias: Sometimes called the "recency effect," recency bias occurs whenever performance is assessed on the basis of recent events, giving undue weight to "right now" behaviors. This clips the true picture of performance and tells only a small part of an employee's story. 
  • Spillover bias: The opposite of recency is spillover, which unfairly assumes that a person's past performance continues to show up in the present. This pessimistic view of others dismisses the notion of a growth mindset and chains people to a past they can't easily overcome.
  • Confirmation bias: Better known as "halo effect," this bias results in an overly positive view of people on the basis of past experiences, personal affinities or pre-conceived beliefs. It leads to favoritism, better reviews and an overall rosier view of performance.

Bias cannot be eliminated altogether, but there are deliberate steps leaders can take to limit its effect on decision-making -- primarily by elevating the voices of others. Here are three:

1. Become a "learn it all."

Instead of presuming to know everything about another person, develop a genuine interest in understanding their unique point of view. This "learn it all" approach fosters curiosity, reveals new insights, and can even strengthen relationships. 

2. Flip the conversation.

Performance reviews are notorious for turning into one-sided monologues dominated by the perceptions of managers. Try reversing the dynamic by asking employees to describe something they wish others knew about them -- their work style, recent achievements, or interests outside of the office. You'd be amazed at how much you don't know about others. 

3. Invite self-critique.

If you can't trust your own assessment, ask for someone else's -- your employee. Every few weeks, or at the end of a project, invite your team  to write their own evaluation. I encourage my clients to use a simple matrix that is broken into two columns: "Do over" and "do again." Employees find the exercise refreshing, since it gives them opportunities to reflect and reframe, and managers are surprised by the insights it provides.  

Fairness and objectivity are essential elements of a robust review process. When managers pay closer attention to the voices of their employees, they're more likely to recognize them for who they really are.