The first number you see rewires your valuation
When you encounter a price guide, a suburb median, or an agent's quote before you form your own view, that figure becomes the reference point your brain measures every later number against. This is , and it is one of the most studied cognitive distortions in decision-making. It hits property buyers hard because every listing starts with a number.
- In a 1974 experiment, a rigged wheel of fortune landing on 10 vs 65 shifted estimates by 20 percentage points on a completely unrelated question .
- In a 1987 real estate study, agents and students were given identical properties with different listing prices — the listing price significantly shifted their valuations across all four measures tested .
- Only 19% of the agents admitted the listing price influenced them, compared to 37% of the students — the experts were just as anchored, but less aware of it .
These are not fringe findings. The effect is large, reliable, and it operates largely outside conscious control.
Knowing about anchoring does not protect you from it
Anchoring is a mental shortcut your brain uses when estimating uncertain values. You latch onto an initial number, then adjust from it. The problem is that the adjustment is almost always too small .
Psychologists Tversky and Kahneman first demonstrated this in 1974 with the rigged wheel of fortune. Participants who saw 65 guessed an average of 45% for the proportion of African nations in the United Nations. Participants who saw 10 guessed 25% . A random number on a wheel shifted their estimates by 20 percentage points on a completely unrelated question.
Wilson et al. (1996) then tested whether knowing about the bias protects you from it. They told participants about anchoring, explained how it would contaminate their responses, and even offered money for accurate answers. The anchoring effect persisted. Forewarning and financial incentives did not eliminate it . The bias operates before deliberate reasoning starts, so willpower does not intercept it. You need a process-based defence instead.
Two types of anchor enter your property search
Understanding where anchors come from helps you spot them before they take hold.
Externally provided anchors are numbers someone else gives you:
- Agent s
- Suburb median prices on listing portals
- A friend saying "that street goes for about $1.2 million"
- Reserve prices announced at auction
Self-generated anchors are numbers you produce yourself, often from incomplete information:
- A property you inspected last week that was listed at $950,000
- The price you paid for your current home
- Your pre-approval limit
Both types create the same bias. Your brain treats them as starting points and adjusts insufficiently from there . A 2024 study by Wegrzyn and Kuta confirmed this pattern holds in housing markets: completely random numbers, with no connection to actual property values, shifted participants' price estimates by up to 10.5% of the asking price .
What was tested | Result |
|---|---|
Random wheel number (10 vs 65) | 20 percentage point gap in estimates |
Manipulated listing price (real estate agents) | Significant shift across all four valuation measures |
Random number before housing price estimate | Up to 10.5% shift in asking price estimates |
The defence is a number of your own, formed first
Every price you encounter before forming your own valuation becomes an anchor. The agent's price guide. The suburb median on Domain or realestate.com.au. The figure your parents mentioned over dinner.
The insight is not that you should avoid all numbers — that is impossible. The insight is that you need to form your own valuation from data before you encounter anyone else's number. Once you have your own figure written down, later anchors still tug at your judgment, but they tug at something you already defined.
A later step in this lesson walks through how to build that valuation from recent sales records. For now, the shift to make is to treat every agent number as information about the agent, not information about the property.