Anchor–Target Compatibility
Studies suggest that an anchor’s scale and meaning can affect how strongly it influences a judgment. Some reported stronger anchoring when anchor and target matched, but the findings do not establish compatibility as a universal requirement.
THE IDEA
Anchor–Target Compatibility
In most studies of anchoring, the anchor is an arbitrary number on the same scale as the target response. Several studies have examined whether this condition is necessary for anchoring to occur.
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Chapman and Johnson (1994): Asked subjects to judge the value of consumer items by indicating the amount of money or additional life expectancy they would demand in exchange for giving up the item. Anchoring occurred if the anchor and response were on the same scale (e.g., both life expectancy) but not if they were on different scales (e.g., monetary anchor and life expectancy response).
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Kahneman and Knetsch (1993): Toronto residents were asked whether they would pay $25 (low anchor) or $200 (high anchor) to clean up lakes. When asked to estimate the average contribution, anchoring occurred (estimates of $14 vs. $36). When asked to estimate the percentage who would pay $100, anchoring did not occur (24% vs. 29%). Thus, anchoring occurred when anchors and responses were both on a dollar scale, but not when anchors were dollars and responses were percentages.
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Strack and Mussweiler (1997): Found that numeric scale agreement alone is insufficient; the underlying dimension also matters in their experiment. Subjects estimated the height or width of the Brandenburg Gate after considering a numeric anchor described as the height or width. Anchoring was stronger when both anchor and target represented the same dimension (both height or both width) and weaker when one was height and the other width.
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Wilson et al. (1996, Experiment 1): Subjects estimated the number of countries in the UN. Some compared the anchor to the UN question, others to the number of physicians in the phone book. Anchoring occurred in both cases, but the effect was numerically smaller (though not significantly) when the anchor was from a different dimension (physicians) than the target (UN countries). The numerical difference was inconclusive; this study does not establish that dimension mismatch reliably reduced anchoring.
When to use it
In salary negotiations, separate base salary from total compensation before comparing offers. Both may be stated in money while including different benefits and costs.
When estimating project costs, identify whether a reference concerns hours, hourly rates or total spending. Convert quantities explicitly rather than assuming a different scale will make an estimate more accurate.
In marketing research, test how people interpret equivalent discounts such as '50% off' and 'save $10'. Do not assume the studies summarized here establish the effect of every pricing format.
When reviewing an estimate, ask whether the initial reference number measures the same quantity as the answer being sought.
FROM THEORY TO EVERYDAY LIFE
In practice
Same-scale compatibility (Chapman & Johnson, 1994)
Participants were asked to value a consumer item by stating how much money or additional life expectancy they would demand to give it up. Anchoring only occurred when the anchor and response were on the same scale (e.g., money-money or life expectancy-life expectancy). When scales mismatched (e.g., money anchor, life expectancy response), no anchoring effect was found.
Same-dimension compatibility (Strack & Mussweiler, 1997)
Participants estimated the height or width of the Brandenburg Gate after seeing an anchor described as either the height or width (all in meters). Anchoring was much stronger when the anchor and target judgment both referred to the same dimension (height-height or width-width) compared to when they referred to different dimensions (height-width or width-height), even though all numbers were on the same numeric scale (meters).
A MOMENT TO REFLECT
Put it to work.
Recall a time when you were influenced by an anchor that was on a different scale or dimension from the judgment you needed to make. How did that affect your decision?
When setting prices or negotiating, how can you ensure that the anchor you present is compatible with the outcome you want to achieve?
Why do you think anchoring effects are weaker when the anchor and target are on different scales or dimensions? What does this suggest about the cognitive processes involved?
References
- — Chapman, G. B., & Johnson, E. J. (1994)
CONTINUE THE CONVERSATION
Source texts
- Heuristics and Biases The Psychology of Intuitive Judgment (Thomas Gilovich, Dale Griffin, Daniel Kahneman)