8. The Anchoring Heuristic (a.k.a. Anchor & Adjust Heuristic)
One last heuristic to introduce, which is rarely confused with availability or representativeness but actually has a similar underlying cognitive mechanism, is the anchoring heuristic.
What Is the Anchoring Heuristic?
The anchoring heuristic applies to numerical reasoning (e.g., money/cost, size, age, and time) when we know or assume the starting numerical value, which then affects our thinking and decisions (Tversky & Kahneman, 1974).
Let’s make this more concrete:
Example: Renting
Let’s return to the scenario in the second post (2. Modes of Processing / Dual Processing).
You are moving to a new city for a job and looking to rent a place. You currently live in a 3,000-square-foot house you inherited. You start looking for rentals in the neighbourhood your coworker suggested, and the biggest place you can find is about 2,000 sq ft. You think there is no way you and your family will be comfortable in such “cramped” quarters. So, without even considering any specific place, you start looking at other neighbourhoods.
What is happening here?
The size of your current house serves as an “anchor” in your reasoning about your future place. Because you start with 3,000 sq ft in mind, a jump all the way down to 2,000 seems significant. However, if you didn’t have that starting point, you might find a 2,000-sq-ft house quite spacious. Certainly, if you currently live in a 1,000-sq-ft place, you would think 2,000 is plenty and amazing! This case also involves an anchoring heuristic, only in the opposite direction.
Note that (as with the other heuristics) relying on this heuristic allows you to make a swift decision based on a small set of information. If the house’s size is truly important to you, engaging in this type of heuristic reasoning is to your advantage. However, if other factors are more important, this heuristic may undermine your efforts to find the best fit.
In this scenario, the anchoring heuristic can be relevant in different ways — the size of the place, number of bedrooms, number of bathrooms, distance from the workplace, cost, age of the building, etc. If you have preconceived notions about any of these numerical parameters, automatic reasoning will be “anchored” to your starting values (which may be desirable or undesirable).
Why does this happen?
There have been different accounts of how and why this phenomenon occurs, as well as the extent to which it indicates rational versus irrational decision-making (e.g., Epley & Gilovich, 2001; Furnam & Boo, 2011; Lieder et al., 2018).
The most widely accepted mechanism — which also aligns with the cognitive concepts discussed in the previous sections — is selective accessibility (Strack & Mussweiler, 1997; Strack et al., 2016). The basic idea behind selective accessibility is that the anchor activates related mental representations, which makes them more accessible during subsequent processing and reasoning.
In the example above, you associate the anchor of the 3000-sq-ft house with a mental representation of everything else that is typical of a house that size. As you consider subsequent rental candidates, this selectively accessible mental representation affects your perceptions and assessments of the new stimuli. In this case, your current anchor makes a 2000-sq-ft house less appealing. Conversely, in the case of a 1000-sq-ft anchor, the same 2000-sq-ft house would be more appealing.
Many factors may affect the degree to which we are susceptible to using the anchoring heuristic, including:
- expertise
- motivation
- personality
- mood
- (e.g., Furnam & Boo, 2011)
Example: Age
When thinking of someone who is 30:
- If you are 10 years old, they may seem “old.”
- If you are 25, not so much.
- If you are 50, they may seem “young.”
In this case, you use your own age as an anchor.
Example: Sales
The classic example of the anchoring heuristic: SALES!
Buy this car — it was originally worth some outrageous amount of money; now, it is still worth an outrageous amount of money, but it is 40% off, so this is a great deal!
