"One study found that the vast majority of scientists
drawn from a national sample showed a strong preference
for "confirmatory" experiments. Over half of these
scientists did not even recognize disconfirmation (modus
tollens) as a valid reasoning form! In another study the
logical reasoning skills of 30 scientists were compared
to those of 15 relatively uneducated Protestant
ministers. Where there were performance differences, they
tended to favor the ministers. Confirmatory bias was
prevalent in both groups, but the ministers used
disconfirmatory logic almost twice as often as the
scientists did." ~Michael J. Mahoney, Publication
Prejudices: An Experimental Study of Confirmatory Bias in
the Peer Review System Cognitive Therapy and Research,
Vol. 1, No. 2, 1977, pp. 161-175.
http://confirmatory-bias.behavioural...w%20System.htm
Modus Tollens
http://en.wikipedia.org/wiki/Modus_tollens