What is the term for the bias that occurs when an observer's initial impressions skew their observations?

The term that reflects the phenomenon where an observer's initial impressions influence their observations is the "Halo Effect." This concept refers to a cognitive bias where the perception of one positive attribute of a person or thing leads to the assumption of other positive traits. For instance, if an observer finds a participant likable or pleasant initially, they may unconsciously rate that participant’s other qualities—such as intelligence or competency—more favorably than warranted.

The Halo Effect typically emerges in various contexts, including performance evaluations, interviews, and even in academic settings, where initial encounters can curtail objective evaluation of subsequent attributes. This bias often skews the validity of observations, which is a crucial concern in research and evaluation practices, as it affects data integrity and the conclusions drawn from such observations.

Understanding this bias is essential for researchers and evaluators to implement strategies that minimize its impact, thereby ensuring more accurate and reliable results in their work.