Students say professors realize their students are under pressure, but are still not about to give up getting the best results in order to preserve students' welfare.

"I think it would be awful for Harvard and the department to lose its concentration and its edge," Verdine says. "God knows it wouldn't be good for science, Harvard, or our students."

Verdine says that students who don't have the emotional stability for graduate chemistry work will discover that very quickly, and either learn to deal with it or choose another lab.

For professors like Verdine, who in the early 1990s was trying to get a tenure offer, lab work can be even more intense. If the lab of a junior professor doesn't produce results, the professor may not get tenure. And that means extra pressure on graduate students in associate professor's laboratories.

"It would be disingenuous to say that my students didn't feel pressure to help me get tenure," Verdine says. "But it created a real esprit de corps in the lab during that year. Students know there is pressure on their professor that translates to them."

But pressure on graduate students today comes largely from their inner drive and much less from their advisors, students say.

"Part of being a graduate student is struggling with things like that," Haushalter says. "There is definitely a mental toughness that you have to develop. You do face a lot of pressures, but they are mostly internal."