Thus many lecturers--including DeVore, whoteaches Science B-29, "Human BehavioralBiology"--purposely use humor to teach moreeffectively.

"If you want people to attend to what you'resaying, you have to appeal to their emotions, notjust their intellect," says DeVore. "Humor hasclassically been one of the safer emotions.

And sometimes humor just occurs spontaneously,to the delight of students.

"Students love when [demonstrations] fail,"says Kirshner, who teaches Science A-35, "Matterin the Universe," "They love it when the professoris humiliated."

Kirshner, known for his extravagantdemonstrations, received a 4.5 rating in thisyears' CUE Guide.

DeVore says students feel less intimidated bybig name professors if they are humorous.

"I try not to take myself seriously," saysDeVore, "because I find that in teaching, it helpsto let people know that deep down inside, I'm justthe barefoot boy from East Texas."

While fake telegrams and blue urine makefor some funny moments, scientists say they arecareful not to cross the line between good andoffensive humor.

"Exacting humor at the cost of someone is justnot funny--it's sad," says Mishra.

Marks says he is "not a practical joker"because certain jokes are more harmful than funny.

Marks says a friend of his one sent apechromosomes, instead of human chromosomes, to aclinical lab for diagnosis. Chromosomes arestructures of tightly coiled DNA, in which defectscan indicate disease.

"[The lab] thought it was a human with acertain form of cancer," Marks says. "I thinkthat's a little bit sick because you're wastingsomeone's time."

Teachers who employ humor in the classroom arelikewise cautious about whom they joke with.

"The trick is drawing the line," says Kirshner,"I don't joke with students who are not doing wellor with people I don't know."

So, given the preponderance of humoramong scientists, is the 'nerd' stereotypebreaking down? The verdict is divided.