impression formation

Meaning: Impression formation is how a perceiver builds a unified opinion of another person from cues such as looks, behavior, and the setting. Perceivers do not average traits evenly. Solomon Asch found that central traits, such as warm versus cold, change how the other listed traits are read, while peripheral traits matter less. Perceivers also lean on implicit personality theories (assumptions about which traits go together) and shortcuts such as the halo effect, in which one positive trait leads to assuming other positive traits. Order matters too. The primacy effect is the tendency for first information to weigh more heavily. The recency effect, where the latest information weighs more, can win when time passes between pieces of information.

On the MCAT: A passage describes participants who read a list of traits about a person, sometimes in different orders or with "warm" swapped for "cold," and then rate that person. Predict that the central trait or the first-presented trait shifts the ratings. It is also linked to the physical attractiveness stereotype, attribution, and stereotypes in social perception.

Common confusion: Impression formation is what the perceiver does when judging someone else. Impression management is what a person does to control how others see them (self-presentation, as in Goffman's dramaturgical approach). Also, primacy is a common pattern, not a fixed rule, so check the timing in the design.