Performance Review Biases and How HR Can Reduce Them

Performance reviews are intended to be objective assessments of contribution and results. In practice, however, human judgement introduces bias, which can distort outcomes, reduce trust, and weaken the credibility of performance systems.

This article explains common performance review biases and outlines how HR can design processes that minimise bias while preserving managerial judgement.

Why Bias in Performance Reviews Matters

Unchecked bias can lead to:

• Perceived unfairness and disengagement

• Inconsistent ratings across teams

• Reduced diversity and inclusion outcomes

• Increased attrition among high performers

Bias does not always stem from intent—it often arises from cognitive shortcuts and system design gaps.

Common Performance Review Biases

1. Recency Bias

Over-weighting recent events while ignoring performance over the full review period.

2. Halo and Horns Effect

Allowing one strong or weak trait to influence the entire evaluation.

3. Leniency and Severity Bias

Managers consistently rating too generously or too harshly.

4. Central Tendency Bias

Avoiding extreme ratings and clustering most employees around the middle.

5. Similarity Bias

Favouring employees who share similar working styles, backgrounds, or perspectives.

Structural Causes of Bias

Bias often increases when:

• Performance criteria are vague

• Reviews rely heavily on memory

• Managers lack review training

• Calibration processes are absent

Well-designed systems reduce the reliance on subjective recall.

HR Interventions to Reduce Bias

1. Clear and Behaviour-Based Criteria

Defining observable behaviours and outcomes reduces interpretation gaps.

2. Multi-Source Inputs

Using peer, cross-functional, or project feedback balances single-manager perspectives.

3. Calibration Discussions

Structured forums help align rating standards across teams.

4. Manager Capability Building

Training managers to recognise bias improves judgement quality over time.

5. Data Review and Trend Analysis

Reviewing rating distributions helps identify patterns of inconsistency.

Sample View: Bias Types and HR Mitigation Actions

Checklist: Bias-Resistant Performance Reviews

☐ Performance criteria are specific and measurable
☐ Managers document performance throughout the cycle
☐ Multiple data points are considered
☐ Calibration forums are conducted
☐ HR reviews rating patterns
☐ Managers receive bias awareness training

Role of HR in Sustaining Fairness

HR acts as the system custodian, ensuring:

• Consistency without rigidity

• Judgement without arbitrariness

• Accountability without micromanagement

Bias reduction is an ongoing discipline, not a one-time fix.

Key Takeaway

Performance review bias cannot be eliminated entirely, but it can be significantly reduced through thoughtful system design, manager enablement, and data discipline. Fair reviews strengthen trust and improve decision quality.