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Measurement of Involuntariness

in Hypnotic Response

 

Response to hypnotic suggestions is typically evaluated in terms of overt behavioral response, but the experience of hypnosis goes beyond publicly observable actions. In the classic instance, hypnotic behavior is accompanied by the subjective conviction that the suggested state of affairs is real, and by the experience of involuntariness in response -- the latter feature known as the classic suggestion effect. The experience of involuntariness has played an important part in theorizing about hypnosis, but it was not incorporated into standard instruments for measuring response to hypnosis, such as the Stanford and Harvard scales.  

In our laboratory, we have used a couple of different involuntariness scales with the HGSHS:A, following up on the work of Patricia Gregg Bowers and her colleagues on the classic suggestion effect (International Journal of Clinical & Experimental Hypnosis, 1982, 1988).

One approach has been a simple 4-point Likert-type scale with labeled poles:

Deliberate, Effortful, Voluntary     1-----2-----3----4    Automatic, Effortless, Involuntary

In a large sample of subjects who received the HGSHS:A (N = 1269), total involuntariness score correlated r = .57 with total objective behavioral score (unpublished data).

Another approach has been a more complex 5-point categorical scale:

A.  I did not respond at all during this time. (Score = 0)
B.  My response was mostly voluntary. (Score = 1)
C.  My response was mostly involuntary. (Score = 4)
D.  The feeling that my response was voluntary was completely intermixed with the feeling that it was involuntary. (Score = 2)
E.  At first my response was voluntary, but then later on it continued to occur involuntarily. (Score = 3)
F.  None of the above. (Unscored)

In a large sample of subjects who received the HGSHS:A (N = 1924), total involuntariness correlated r = .65 with total objective behavioral score.

Obviously, at least one possibility is missing: that a response started out feeling involuntary, and then became voluntary.  For a brief period of time we added this category to the list, generating a 6-point categorical scale:

A.  I did not respond at all during this time. (Score = 0)
B.  My response was mostly voluntary. (Score = 1)
C.  My response was mostly involuntary. (Score = 5)
D.  The feeling that my response was voluntary was completely intermixed with the feeling that it was involuntary. (Score = 3)
E.  At first my response was voluntary, but then later on it continued to occur involuntarily. (Score = 4)
F.  At first my response was involuntary, but then later on I had to continue it voluntarily. (Score = 2)
G. None of the above. (Unscored)

The option of "None of the Above", while satisfying in rhetorical terms, is unscored and thus completely uninformative about what the subject's experience actually was.  Accordingly, we eliminated it in the final version of our revision.  We also rearranged the options so as to form a continuous scale of involuntariness.  As of 2003, this categorical scale is the one we use in our own screening procedures, and it is the one included in the sample HGSHS:A response booklet provided elsewhere on this website. 

A.  I did not respond at all during this time. (Score = 0)
B.  My response was mostly voluntary. (Score = 1)
C.  At first my response was involuntary, but then later on I had to continue it voluntarily. (Score = 2)
D.  The feeling that my response was voluntary was completely intermixed with the feeling that it was involuntary. (Score = 3)
E.  At first my response was voluntary, but then later on it continued to occur involuntarily. (Score = 4)
F.  My response was mostly involuntary. (Score = 5)

Reasonable people can disagree about the proper ordering of options C and E, but an unpublished psychometric analysis revealed that this one showed slightly better correlations with total HGSHS:A score than the reverse.


This page was last revised 09/13/2013.