How Companies Can Make Peer Evaluations Fairer

Peer evaluations—assessments of employees by their colleagues—often serve as the basis for bonuses and promotions. A new study from WU Vienna shows that teams evaluate one another more fairly when their success has first been externally validated. The timing of evaluations can therefore be a powerful lever for increasing fairness in the workplace.

How Biases Arise

In team-based work environments, employees are often asked to evaluate the performance of their colleagues. These assessments are prone to so-called ingroup bias: people tend to rate members of their own group more positively than others. In diverse teams, differences such as background, gender, or experience can become even more salient. “In diverse teams, certain groups may systematically receive lower evaluations,” explains WU professor Gerhard Speckbacher. Such biases can significantly influence important personnel decisions, including bonuses, promotions, and salary adjustments.

Better Timing Leads to Fairer Evaluations

In two experiments involving a total of 247 volunteer students, Gerhard Speckbacher and Martin Wiernsperger investigated how the timing of peer evaluations affects evaluation bias. Participants worked in teams and received feedback on their team’s performance either before or after evaluating one another.

The results were clear: when peer evaluations took place after the team’s success had been externally confirmed, the assessments were significantly less biased. “When a positive outcome is validated by an external source, team members identify more strongly with the team as a whole. This reduces subgroup thinking and lowers the tendency to favour members of one’s own group,” says Gerhard Speckbacher. “The timing of evaluations is a simple yet effective lever that organizations can use to make performance assessments fairer.”

Detailed study results and further information

Gerhard Speckbacher; Martin Wiernsperger (2025). Peer evaluations in diverse teams: How external validation of team performance influences ingroup favoritism. In: Accounting, Organizations and Society. Available at https://doi.org/10.1016/j.aos.2025.101595

Press contact

Julia Kreimel
Science Communication

Tel: +43‑1‑31336‑5478
Email: julia.kreimel@wu.ac.at