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IB DP Psychology — Cognitive Approach | SL & HL | Paper 1
🎯 Learning Intentions By the end of this note, you will be able to:
- Define anchoring bias and confirmation bias using IB-aligned terminology.
- Explain how cognitive biases arise from heuristic thinking and why they represent systematic errors in human reasoning.
- Describe the role of prior beliefs and initial information in shaping subsequent judgements and decisions.
- Evaluate research evidence for anchoring bias and confirmation bias using supporting and opposing studies in ACAS format.
- Apply anchoring bias and confirmation bias concepts to a real-world case study from the cognitive perspective.
- Discuss the extent to which cognitive biases provide a complete explanation of flawed human decision-making.
- Analyse anchoring bias and confirmation bias using relevant concept areas: Bias, Causality, Measurement, and Perspective.
Introduction & Context
Imagine you walk into a shop and see a jacket with a price tag reading "Was £200, now £80." You feel like you are getting a bargain, but stop and ask yourself: how do you actually know the jacket was ever worth £200? The original price was set by the retailer, and yet it has powerfully shaped your sense of what a fair price looks like. You have been given a number, and that number has anchored your entire evaluation of the deal.
Now imagine a different scenario. You have a strong opinion about a political candidate. You come across two news articles: one that criticises the candidate and one that praises them. Research consistently shows that people spend more time reading, and find more convincing, the article that agrees with what they already believe. They do not weigh both pieces of evidence equally but seek out confirmation of what they already think. These two everyday tendencies: anchoring and confirmation are among the most well-documented and consequential patterns in human cognition. Understanding them is central to the cognitive approach in IB Psychology.
🔗 Analogy Think of your mind as a ship navigating in fog. The first landmark you spot becomes your reference point, you steer relative to it, even if it turns out to be in the wrong place. That is anchoring. Now imagine you are so convinced you know where you are that you only look for landmarks that confirm your position, ignoring ones that suggest you are off course. That is confirmation bias. Both errors stem from the same source: the mind's tendency to take shortcuts rather than process every piece of information from scratch.
Core Concepts
When psychologists began studying human decision-making in the 1970s, they expected to find that people reason like statisticians — gathering evidence, weighing probabilities, and arriving at logical conclusions. What they found instead was far more interesting. People rely on mental shortcuts, known as heuristics , that allow them to make quick decisions without exhausting cognitive resources. Most of the time, heuristics work well enough. But they also introduce predictable, systematic errors, what psychologists call cognitive biases.
A cognitive bias is not a random mistake. It is a consistent, directional error in thinking that occurs because of the way the mind processes information. Two of the most important and widely studied cognitive biases are anchoring bias and confirmation bias . Both emerge from the same underlying tendency: the mind's preference for using existing information as a shortcut rather than engaging in effortful, systematic reasoning.
📖 Key Definition — Cognitive Bias A cognitive bias is a systematic pattern of deviation from rational judgement in which inferences about other people and situations are drawn in an illogical