I have an experiment I would love to run. I would love to compare the actual winners of Olympic events with the pre-event favorites, in two categories: Those events with objective standards (time, distance, etc) and those that are judged (e.g. skating). My hypothesis is that in judged events, barring a disaster (e.g. falling in a skating jump) judges tend to give high marks to those who they come in expecting to win. I would expect that for people deeply tied into a sport (which Olympic judges are) it is impossible to totally separate the contestant's past body of work from their current performance. I therefore would guess that favorites fail to win at objectively measured events more often than in judged events (again barring Michelle-Kwan-like falls).
Update: In another great moment in Coyote's reinventing the wheel, a reader emails to say that this phenomenon is called "anchoring":
Anchoring or focalism is a term used in psychology
to describe the common human tendency to rely too heavily, or "anchor,"
on one trait or piece of information when making decisions.
During normal decision making, individuals anchor, or overly rely,
on specific information or a specific value and then adjust to that
value to account for other elements of the circumstance. Usually once
the anchor is set, there is a bias toward that value.
This apparently occurs even when the number has nothing to do with the decision:
according to Daniel Kahneman if an audience is asked firstly to memorise the last 4 digits of their social security number and then to estimate the number of physicians in New York the correlation between the two numbers is around 0.4"”far
beyond what would be expected by chance. The simple act of thinking of
the first number strongly influences the second, even though there is
no logical connection between them.
I would presume that a number that was more related, like a figure skating pairs couple's world ranking upon entering the competition, would have an even greater impact on the decision.