The Art of Impression Formation: First Impressions and Beyond

Every time you meet someone new, your brain immediately gets to work – piecing together observations, making inferences, and building a mental portrait of that person. This process, known as impression formation, is not a simple snapshot. It is a dynamic, ongoing construction that shapes how we judge, relate to, and interact with others. In social psychology, impression formation refers to the processes by which different pieces of knowledge about another person are combined into a global or summary impression. Understanding how this works reveals just how complex – and how fallible – our everyday social judgments really are.

The pioneering work of Solomon Asch
Central traits: the anchors of our impressions
How we integrate information: adding versus averaging
The adding model
The averaging model
The primacy effect: why first impressions stick
The recency effect: when the latest information wins
Impression formation as an ongoing process
Why impression formation matters

The pioneering work of Solomon Asch

No discussion of impression formation is complete without Solomon Asch, the social psychologist whose groundbreaking 1946 experiments laid the foundation for how we understand person perception today. Asch was influenced by Gestalt psychology, which held that the whole is greater than the sum of its parts. He applied this idea directly to social perception: we do not simply add up a person’s individual traits to form an impression. Instead, we integrate them into a unified, coherent whole.

In his classic experiments, Asch presented participants with a list of personality traits describing a fictional person. Two groups received an identical list, except for one word – one group heard the person described as “warm,” the other as “cold.” The results were striking. Despite every other trait being the same, the impressions formed were dramatically different. People who heard “warm” rated the target as generous, happy, good-natured, and sociable, while those who heard “cold” formed largely negative impressions. Asch found that very different impressions emerged based on this single characteristic, and the meaning of the surrounding traits seemed to shift depending on whether warmth or coldness was present.

This finding led Asch to one of his most important conclusions: not all traits carry equal weight.

Central traits: the anchors of our impressions

Asch introduced the concept of central traits – characteristics that exert a disproportionately strong influence on the overall impression we form of someone. The traits of warm and cold are known as central traits, which are characteristics that have a very strong influence on our impressions of others. In contrast, traits like “polite” or “blunt” – which Asch also tested – barely shifted overall impressions, making them peripheral traits.

Central traits do two important things. First, they lead us to infer other traits that were never mentioned. A person described as “warm” is quickly assumed to be kind, sociable, and generous – even if none of those qualities were stated. Second, central traits color how we interpret every other trait in the list. When a person is described as “warm” and “intelligent,” the meaning of “intelligent” seems considerably more favorable than when the same word appears alongside “cold.”

The practical implication is significant: in the field of psychotherapy, studies have indicated that therapists’ warmth, empathy, and genuineness are among the most important traits in establishing a strong and trusting relationship with clients. Warmth, it turns out, is a powerful social signal across many real-world settings – from job interviews to first dates.

It is worth noting, however, that context matters. Asch himself acknowledged that any trait can be central or peripheral depending on the surrounding context, meaning no trait is permanently fixed as a central one – its weight shifts based on the other information present.

How we integrate information: adding versus averaging

Once we begin collecting information about someone, how do we combine it all into a single impression? Two competing models have been proposed to explain this process.

The adding model

The adding model, proposed by Norman H. Anderson in 1965, suggests that we form impressions by summing up the individual values of the traits we observe. The more positive traits a person has, the more favorable the impression. Under this model, adding any positive trait – even a mediocre one – always improves the overall impression, because every new piece of information contributes its value to the running total. Anderson’s early research examined whether impressions follow an averaging or adding rule, laying the groundwork for the field of cognitive algebra in person perception.

The averaging model

Anderson later refined his position with the averaging model, which accounts for a counterintuitive finding: adding a mildly positive trait to an already very positive impression can actually lower the overall evaluation. Why? Because the new, lukewarm trait pulls the average down. A set of two moderate and two extreme adjectives produced a less extreme response than a set of only two extreme adjectives – a result inconsistent with simple addition, but consistent with averaging.

The averaging model also recognizes that traits are not weighted equally. Some carry more influence than others, and their relative impact depends on the overall context in which they appear. Traits are weighted according to the frequency of past experience, the degree to which experiences match existing knowledge about a person, and the perceiver’s current internal state or mood. This makes the averaging model a more realistic – if more complex – account of how impressions are actually formed.

The debate between the two models is not entirely settled. Research has shown that neither simple summation nor simple averaging is an exclusively valid combinatory principle – which rule applies depends partly on situational factors.

The primacy effect: why first impressions stick

Of all the factors that shape impression formation, the primacy effect is one of the most powerful and well-documented. The primacy effect describes the tendency for information learned first to be weighted more heavily than information learned later.

Asch’s own research demonstrated this clearly. Participants who heard a list of traits beginning with positive qualities (such as “intelligent, industrious, impulsive, critical, stubborn, envious”) formed far more favorable impressions than those who heard the exact same traits in reverse order. Rather, Asch found that the participants who heard the first list, in which the positive traits came first, formed much more favorable impressions than did those who heard the second list, in which the negative traits came first.

Why does the order of information matter so much? One reason is that humans are cognitive misers – because we want to conserve mental energy, we pay more attention to information that comes first and progressively less to information that follows. Early traits also set an interpretive frame: they establish a preliminary impression that colors how all subsequent information is read. A person described first as “intelligent” and then as “stubborn” will be judged more favorably than one described first as “stubborn” and then as “intelligent” – even though both descriptions contain identical information.

Interestingly, individuals described as “fun, witty, and vicious” are typically rated more favorably than those described as “vicious, witty, and fun,” despite the semantic equivalence of these statements – a clear illustration of how sequence, not content alone, drives judgment.

Mood also plays a role. Research found that positive mood increased the primacy effect, consistent with a more assimilative, holistic processing style, while negative mood eliminated the primacy effect, consistent with a more accommodative, externally focused style. This means our emotional state at the moment of meeting someone can determine how much their first impression truly “sticks.”

The recency effect: when the latest information wins

The primacy effect does not always dominate. Under certain conditions, the most recently received information carries the greatest weight – a phenomenon known as the recency effect.

Recency effects, in which information that comes later is given more weight, are much less common than primacy effects but may sometimes occur. Luchins (1957) demonstrated this in his “Jim” studies, where participants read passages describing a fictional person first as extroverted, then as introverted (or vice versa). When a time gap was introduced between the two passages, a recency effect emerged – participants had partially forgotten the earlier information and weighted the more recent description more heavily.

Recency effects also appear in performance-based contexts. In competitions like the Eurovision Song Contest and ice skating, higher marks have been given to performers who went last – suggesting that in certain evaluative settings, being last is just as advantageous as being first.

The conditions that determine whether primacy or recency prevails include the time elapsed between pieces of information, the perceiver’s motivation, and whether they have been asked to form a definitive impression early or are still keeping an open mind. In general, primacy can lead to assimilation of early information into a global impression, create an anchor against which later information is compared, or cause people to actively revise their perception.

Impression formation as an ongoing process

One of the most important things to understand about impression formation is that it does not end the moment you first meet someone. Impressions are updated – sometimes substantially – as new information arrives. Under certain conditions, people do revise their impressions, especially when confronted with strongly disconfirming evidence. This revision process depends on factors such as motivation, need for accuracy, and whether the perceiver holds pre-existing stereotypes.

That said, revision is often harder than it should be. Once an impression is formed, people tend to engage in confirmation bias – seeking out or remembering information that supports their original evaluation. This means early impressions can have a lasting grip, shaping not just what we notice but what we remember about a person.

Negative information tends to be especially sticky. Consistent with negativity bias, negative behaviors are seen as more indicative of an individual’s character, particularly in situations involving moral issues, and extreme negative behavior is considered more predictive of personality traits than less extreme behavior. This asymmetry explains why a single bad act can overshadow dozens of positive ones in our overall judgment of a person.

The configural model – Asch’s original framework – captures this well. The configural model suggests that people form cohesive impressions by integrating traits into a unified whole, adjusting individual traits to fit an overall context rather than evaluating each trait independently. Rather than processing each new piece of information in isolation, we constantly revise and reinterpret each part in light of the whole picture we are building.

Why impression formation matters

The mechanisms behind impression formation have real-world consequences far beyond casual social encounters. In hiring decisions, courtroom judgments, medical consultations, and political elections, the impressions people form quickly – and often based on limited information – can carry enormous weight. Trait impressions from faces influence many consequential decisions even in situations in which decisions should not be based on a person’s appearance.

Understanding the mechanics of impression formation – the outsized role of central traits, the pull of early information, the occasional correction by recency, and the adding versus averaging of what we observe – is the first step toward more deliberate, accurate, and fair social judgment. Our impressions of others feel immediate and certain, but beneath that feeling lies a surprisingly complex cognitive process, one that is shaped as much by how and when we receive information as by what we actually observe.

What do you think? Given how powerfully the primacy effect influences our judgments, how might you deliberately slow down your impression formation process when meeting someone new? And if you have ever significantly revised a strong first impression of someone, what kind of evidence was strong enough to change your mind?

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Table of Contents

The pioneering work of Solomon Asch 🔗

Central traits: the anchors of our impressions 🔗

How we integrate information: adding versus averaging 🔗

The adding model 🔗

The averaging model 🔗

The primacy effect: why first impressions stick 🔗

The recency effect: when the latest information wins 🔗

Impression formation as an ongoing process 🔗

Why impression formation matters 🔗