Speech pauses like you know and uh more frequent among humanities professors

The following article of January 3, 2004 by Michael Erard in the New York Times refers to various studies about speech disfluencies such as "uh" or "um".

Interesting is one study showing that speech pauses such as "you know" and "uh" are more frequent among humanities professors and social scientists. As Erard writes:

But it may be Nicholas Christenfeld, a psychologist at the University of California, San Diego, and other researchers who have come up with the most appealing findings. He counted uhs among professors giving lectures and found that the humanities professors say you know and uh 4.85 times per minute, social scientists 3.84 and natural science professors 1.39 times, which, he said, suggests that humanists have more expressive options from which to choose.

We suspect, however, that it means that the natural science professors are lecturing about more certain factual materials, whereas the social scientists and humanities professors need these verbal pauses to "construct" their statements about things which - in the last analysis - are relatively more uncertain.