Citation Needed (Psychology Study)

Quote:

I used to know a professor of psychology who conducted little tests with his students by choosing random times in his classes to interrupt the lecture and ask the students to write anonymously exactly what they had been thinking at that particular moment. No cheating, he would explain; they had to write what was on top of their mind. Probably you can get psychology students to do that. The students’ responses were correlated against the time into the lecture at which the interruption occurred. As I recall, some 75% of the students were thinking about the lecture as deep into the lecture as 5 minutes. So far, so good, I suppose, but only after 15 minutes or so, he had lost the majority of the class. I think it was about at the 25-minute point that the results showed that the probability was about 0.7 that a given student was having a sexual fantasy. Perhaps again this is just psychology students.

Does this quote ring any bells?

I copied the quote from a book published back in the early 1990s from one
of the libraries around here, but I don't know who did the study and where
they published it. The guy who wrote the book is probably dead now, so I
cannot ask him.

via International Skeptics Forum http://ift.tt/1SQBYDl