The research by academics at the University of British Columbia studied the feedback from customers of a healthcare organisation, a bookshop and a golf club.

For the bookshop study, research participants were shown videos of interactions between sales staff and customers, with the sales assisitant a white man, black man or white woman. Even though the assistants’ actions were pre-scripted, participants rated the white man’s service 19% higher than that of the other two.

Study co-author professor Karl Aquino warned that if surveys are not constructed carefully, anonymous feedback “is often more about consumers’ subjective biases than any objective assessment of employee performance”.

Read more about the research at the university’s website. The full study is due to be published in the journal of the Academy of Management.