A mental representation is a body of knowledge that an individual has stored in memory. Mental representations influence social beliefs and behaviours. The raw materials of first impressions are appearance, behaviour and choices. There are several ways in which we form impressions:

1. Physical appearance
   It is universal that physical beauty calls up positive expectations. Physical beauty has a pervasive influence on our impressions of other people. Certain patterns of facial configuration (e.g: babyface) also has an influence on our impressions of other people.
2. Non-verbal communication
   People like others more when they express their feelings non-verbally more than when people less expressive individuals. People in individualistic cultures like it when someone orients their bodies towards us. Impressions formed from non-verbal communication are often accurate. Visual cues and voice cues are important in forming impressions of other people.
3. Familiarity
   Mere exposure to another person increases liking. Familiarity alone can be a basis for developing a positive impression and feelings of liking for another person.
4. Environments
   Perceivers seem capable of forming fairly accurate impressions of others by observing the physical spaces they occupy. This also holds for virtual environments, such as social-media.
5. Behaviour
   This is the most reliable cue for developing an impression of another person.

Attractiveness is helpful for men when applying for both masculine and feminine jobs and only helpful for women when applying for feminine jobs. It may be harmful to women when applying for masculine jobs. People use the wrong cues when trying to spot deception. People should look at body language, instead of verbal communication and the face.

Rarity or uniqueness is what makes a characteristic stand out. Salience refers to the ability of a cue to attract attention in its context. Salience is highly dependent on the context. Salient cues dominate impressions. Cues have no meaning in itself, but our interpretations of those cues, using mental representations have meaning. Associations and our current thoughts help us interpret cues.

Members of different cultures have different associations and therefore arrive at different interpretations for the same behaviour. Accessibility is the ease and speed with which information comes to mind and is used. Accessibility highly influences our interpretations. Knowledge becomes accessible and can influence our interpretations in three ways:

1. Concurrent activation
   Knowledge can become accessible because of concurrent activation. This can be caused by expectations, as expectations can activate related information, which we use to interpret behaviour.
2. Recent activation
   Recent activation of mental representations can shape our interpretations of cues. Priming is the activation of mental representation to increase its accessibility and thus the likelihood that it will be used. Primed concepts remain accessible and influence later interpretations for 24 hours.
3. Frequent activation
   Concepts that are frequently activated are more accessible to us and influence our interpretations.

A correspondent inference is a process of characterizing someone as having a personality trait that corresponds to the individual’s observed behaviour. Correspondent inferences are justified when the individual freely chooses to perform the behaviour, the behaviour has unique effects that other behaviours do not and the behaviour is unexpected rather than typical. The correspondence bias is the tendency to draw correspondence inferences, even when they are not justified. When people pay specific attention to the situation, the correspondence bias is reduced or reversed. Culture also sets limits on the correspondence bias. When the correspondence bias occurs, roles make the person.

Superficial processing refers to relying on accessible information to make inferences or judgements while expending little effort in processing. Systematic processing is giving thorough, effortful consideration to a wide range of information relevant to a judgement. Systematic processing requires motivation and the ability to do so.

Causal attribution refers to a judgement about the cause of a behaviour or other event. People see salient causes as more probable causes of behaviour. Attributions can also be based on accessible causes, those that are already activated in our minds. Information about potential causal factors that are present when the event occurs and absent when it does not may also shape attributions. Behaviour might be explained by something about the actor, the target of the behaviour or the particular situation or circumstances.

Discounting is reducing a belief in one potential cause of behaviour because there is another viable cause. This is changing the initial correspondent inferences. Using causal reasoning to correct the initial correspondence impression takes conscious effort and thus does not happen a lot.

People usually expect certain traits to go together. These patterns of associations among traits are called implicit personality theories. An impression of a person’s diverse behaviours and traits are also created by causal links among them. People tend to give negative information more weight than positive information when we integrate impressions. This is because negative information is generally unexpected. Accuracy is one of the strongest motivations for working hard on forming an impression. People like to have accurate impressions of people. In order to do this, people need to spend more time on forming the impression and questioning whether third-party information about a person is accurate. Feeling accountable, anticipating future interaction and suspicion of the information we obtain make us think more carefully and go beyond a first impression to a more fully considered one.

Accuracy is not always the primary goal of person perception, as maintaining relationships can be a strong motivator as well. The desire to see the world in a way that will result in a good outcome for ourselves is another goal that may supersede accuracy. Only when both motivation and cognitive ability are available we attempt to counteract potential biases in how we see other people

People use impressions and act on them. When people process quickly and superficially, they generally rely on their past judgements of an individual. People tend to rely on past judgements, even if the past judgements were made in circumstances that create bias.

Impressions resist change, partly because a first impression can alter the interpretation of later information. Once formed, our beliefs about other people are slow to change. The primacy effect is a pattern in which early encountered information has a greater impact than subsequent information. The perseverance bias is the tendency for information to have a persisting effect on our judgements even after it has been discredited. Impressions shape our interpretations. The most effective way to reduce or eliminate the perseverance bias is to explicitly consider the opposite possibility.

People prefer to ask diagnostic questions in order to test their hypotheses about impressions, but often fail at thinking of proper diagnostic questions. A self-fulfilling prophecy is a process by which one person’s expectations about another become reality by eliciting behaviours that confirm the expectations. People find it difficult to recognize the effect of their own actions on others. The self-fulfilling effects of a perceiver’s expectation become weaker as the person being perceived has strong views about himself. Self-fulfilling prophecies can also be foiled when targets are aware of the perceivers’ expectations. Self-fulfilling prophecy effects are also weaker when the targets are more concerned about conveying an accurate impression than making the interaction go smoothly and pleasantly.

People prefer to ignore information that is inconsistent with an impression. Unexpected information is more salient. People also generally try to explain inconsistencies in impressions. They try to attribute inconsistencies to situational factors. If people are actively looking for change in an individual, they are able to perceive it.