What is Anchoring bias in IB Psychology?

Anchoring bias is a key topic in IB Psychology covering core concepts, theories, and research relevant to the IB Psychology syllabus, examined in Paper 1 and Paper 2.

How is Anchoring bias assessed in IB Psychology?

Anchoring bias is assessed in Paper 1 Section A and B and may appear in Paper 2. Understanding the mark scheme is essential for scoring full marks.

How do I write a high-scoring answer on Anchoring bias?

A high-scoring answer requires a clear command term response, relevant theory with supporting evidence, critical evaluation, and a conclusion.

IB Psychology Anchoring bias Notes

Study Notes

Mark Scheme

SECTION A MARK SCHEME (4 marks) Must Include: • First information presented = anchor • Insufficient adjustment mechanism • Anchor restricts judgment range despite being arbitrary • Named study (Tversky & Kahneman wheel of fortune) • Two anchor conditions (10 vs 65) • Biased estimates (UN membership estimates) • Arbitrary anchor produced systematic bias

Link Formula: "The arbitrary anchor [value] constrained estimates toward [direction], showing [outcome] despite knowing the anchor was irrelevant."

Watch Out: Don't say the anchor "affects thinking"—explain the mechanism: insufficient adjustment from starting point.

SECTION B MARK SCHEME (6 marks) 0 marks: No relevant knowledge. 1–2 marks: Basic definition; minimal application. 3–4 marks: Anchor mechanism described; partial application. 5–6 marks: "Insufficient adjustment" is the correct mechanistic term; Tversky and Kahneman credited; wheel of fortune study accurately described with both anchor conditions (10 vs. 65); explicit link to irrelevant initial information biasing judgment; clear application to scenario.

Why Full Marks

"Insufficient adjustment" is the correct mechanistic term; Tversky and Kahneman credited; wheel of fortune study accurately described with both anchor conditions (10 vs. 65); explicit link to irrelevant initial information biasing judgment.

Model Answer

High-Scoring Sample

Section A Sample Answer

Anchoring bias is a cognitive heuristic where an individual relies too heavily on the first piece of information offered (the "anchor") when making decisions. The mechanism involves an insufficient adjustment from that starting point. Once an anchor is set, it behaviorally restricts the range of judgment, even if the anchor is clearly arbitrary or irrelevant to the actual decision.

This was investigated by Tversky and Kahneman using a wheel of fortune experiment where participants saw a wheel land on either 10 or 65. Those who saw 10 gave much lower estimates for the percentage of African countries in the UN than those who saw 65, despite the number being random. This demonstrates how anchoring bias causes judgment errors, showing that human cognition is susceptible to being biased by irrelevant initial information.

Section B Sample Answer

Anchoring bias is a cognitive bias where individuals rely too heavily on the "anchor" (the first piece of information). This occurs because the anchor primes associated information in memory, causing selective accessibility where anchor-consistent evidence is more available. If a student is told the hub increases speed by "50%," that becomes the anchor. Even with a 20% improvement, they may perceive failure. This demonstrates anchoring bias because the student's subjective appraisal of their performance is distorted by the initial anchor, which primes them to seek information consistent with a 50% gain.