From talking to people on Skeptiko, from my own experiences, from talking to friends and family, and from reading research on mediums, it seems to be hummingbird statements which drive people to believe in psychic abilities. Or at least to give people pause in their skepticism. What you hear over and over again is "there is no way they could have known that" Our intuition tells us that these experiences are far too unlikely to be due to chance, and it becomes very hard to shake the feeling that something magical is happening when these kinds of hits are made.
So is this correct? Are these experiences unlikely, due to chance? It turns out that they aren't.
One way to look at this is to consider whether these statements are as specific as they appear (i.e. there is only one opportunity for a match?). If we go back to the Dr. Phil show, the actual statement made by the Psychic was "I'm supposed to talk about a hummingbird." There are multiple ways in which this could have been a hit, including specific hits. For example, it could have been a hit for any of the other audience members, it could have referred to a hobby, a location, an occupation, etc., or it could have been one of the many statements made by the psychic that wasn't a hit and was simply passed over and forgotten. If you go through a reading just keeping track of statements which have the potential to be a hummingbird statement (i.e. they have the potential to be regarded as eerily specific, if a match is made), you see that many such statements are made in rapid succession, and are simply discarded in the absence of a match. Multiple opportunities dramatically increase the probability of a match, yet our intuition judges the probability as though only one opportunity was taken.
But we don't even need to guess at whether or not these statements are more probable than they seem. Their presence, due to chance, has been assessed in a few studies.
In Emily Kelly's study of mediums who seem to give accurate information, 12 of the 200 control readings, and 14 of the 40 target readings generated comments like "I knew this was the correct reading," “I don’t see how it could be anything other than (X reading),” or the reading "stood out and contained many accurate descriptions". One example of a hummingbird statement was a reference to the Wizard of Oz (in the control group).
In a different kind of study looking at the Ganzfeld studies, 20 out of 128 mentation reports were selected as having remarkable correspondences. Fourteen of these remarkable correspondences occurred by chance, while six corresponded to the target picture (the rate of production of hummingbird statements was the same for "psi" as it was for "chance").
I mentioned in a previous blog post that the outcomes which are measured in mediumship studies is all over the place, which dramatically increases the probability of obtaining false positives. I would propose that looking for hummingbird statements has strong external and face validity, as an outcome measure. That is, it seems to be the outcome measure people use informally to justify their belief in psi, and in the Kelly study, more hummingbird statements were generated in the target readings than in the control readings.
