The pull of a number you just saw
A number you KNOW is random still pulls your next guess toward it. It is one of the most repeated findings about human judgment.
A number lands in your head: a price, a score, a number on a wheel.
Your next estimate starts FROM that number and adjusts, and the adjusting stops too soon.
Seeing your own drift, measured across days, is what loosens the pull.
Then and now
From a wheel-of-fortune demonstration to one of the best-replicated effects in psychology, confirmed across dozens of labs and thousands of people.
Tversky, A. and Kahneman, D. (1974)
Where it began“Judgment under uncertainty: Heuristics and biases”
Science, 185, 1124-1131
The founding paper: estimates assimilate toward an initial value, even one produced by a wheel of fortune the participants watched spin.
Klein, R. A. and 50 colleagues (2014)
State of the art“Investigating variation in replicability: A "many labs" replication project”
Social Psychology, 45, 142-152
Thirty-six labs re-ran classic effects on thousands of people: anchoring replicated everywhere, among the most robust effects tested.
What we do and do not claim
The flashed number was random, and the page says so the moment you answer. Leaving you thinking it meant something would be manipulation, not teaching.