Four ways bias enters every interview
Affinity. Halo. Contrast. Confirmation. All of them, every round.
Bias in interviews operates through four mechanisms, not all of them obvious. Affinity bias: interviewers rate candidates more favourably when they perceive similarities in background, communication style, or experience. Halo and horn effects: a strong or weak early impression influences the assessment of all subsequent responses.
Contrast effects: the order candidates are interviewed affects their assessments. A candidate following a strong candidate is rated lower than in isolation; one following a weak candidate is rated higher. Confirmation bias: panel members who form an impression early record notes that confirm it and discount contradicting evidence.
None of these are deliberate. All of them are features of how human cognition operates under load. Awareness alone does not eliminate them. Process design does.