Perceptual biases are certain tendencies to perceive things in one way or another. They have the effect of closing us off from alternative perceptions that may be more accurate.


Stereotypes are judgements about people and groups based on assumptions about groups to which they belong. They are based on generalisations (assuming everyone in the group shares certain qualities) and simplistic thinking (making judgements without sufficient knowledge).

Stereotypes can be neutral (businessmen wear suits), positive (women are kinder), or negative (men are poor communicators). However, what is a positive or neutral stereotype for one person may be negative to another (e.g. women are naturally giving). Stereotypes came from relating beliefs and concepts that are not necessarily attached to each other (e.g. women and nurturing; men and chivalry).

 Finally, stereotypes are learned, and can be unlearned.

2-Halo effect

This refers to the tendency to make positive judgements about a person of whom we have a positive impression (e.g. she’s cooperative in class, so we assume that she is cooperative at work; he’s a great sportsman, so he is probably trustworthy). 

We can also make negative judgement because of the halo effect (e.g. the employee had difficulty understanding a process, so he must be slow). The media use the halo effect (e.g. a popular singer is assumed to be an expert on breakfast cereals or make-up).

3-Similar to me

This refers to our tendency to perceive more favourably others who are like us. Research shows that when superiors rate their subordinates, they tend to give higher ratings to those who most resemble them, for instance, in race, age, work habits, values, and style of dress.


Attribution – The way we explain certain behaviours.

Stereotype – An over-generalised, often false belief, about a particular group of people, usually but not always negative


Attribution is making judgements about the causes of behaviour. Generally, we make inferences about others from their behaviour, and we often ignore other possible explanations of their behaviour (e.g. someone falls off a ladder, and we assume he has been careless, whereas he might have had a dizzy spell). Also, we make judgements about whether causes lie within or outside the person (i.e. whether they are due to personality or something external e.g. a colleague loses her job. Is it because she is a poor worker, or that the organisation’s need changed? You find yourself without friends. Is it that you are unattractive or difficult to get along with, or that others are getting mixed signals from you and don’t know that you want to be friends?).

Some ways to ensure more accurate perceptions of others are to:

  • observe the person in a range of situations (refer to earlier notes on personality traits)
  • look for the person’s motives in behaving as she/he does
  • consider other explanations for the behaviour
  • Talk with people (not just one person) who have known the person for a lengthy period

5-Perceptual change

Our perceptions are often based on our beliefs about the world around us. Over time, we have expressed opinions, felt emotions and taken actions based on these perceptions, which increases our commitment to them. They have become part of who we are or who we want to be.

  • Cognitive dissonance is a concept that partly explains this. We feel psychological discomfort when our behaviour and our beliefs are in conflict (dissonant). Therefore, once we say or do something, we tend to justify it rather than admit that we were wrong or unwise
  • Perceptual defence refers to strategies that we use to avoid cognitive dissonance or to avoid inner change (which can be difficult). We use these strategies to protect or defend our perceptions when they are challenged by new experiences or information.
    • Denial – Denying information, evidence or the existence of things we do not believe in (e.g. People work in factories because they don’t have the brains to get better jobs. You can’t convince me otherwise).
    • Modification or distortion – Conflicting information is explained away by associating it with other ideas (e.g. I admit he is intelligent, but he’s at the factory because he has no initiative to get ahead).
    • Recognition but refusal to change – This usually means that while the information is accepted, it is seen as an exception (e.g. Sure, he’s intelligent, but he’s different).

Change in perception – This may be a very small acknowledgement of the conflicting perception. We tend to change our perceptions bit by bit rather than all at once (e.g. well, some factory workers are smart). The easiest perceptual change is accommodation – finding a way to fit the new perception into our old belief system (e.g. I suppose things are changing. Factory work isn’t as mindless as it used to be).