Is stress good or bad for you?

My work team leader sent me a link to a Newsweek article on stress and found this interesting.

In the 1970s and '80s, Salvatore Maddi, a psychologist at the University of California, Irvine, followed 430 employees at Illinois Bell during a companywide crisis. While most of the workers suffered as their company fell apart—performing poorly on the job, getting divorced and developing high rates of heart attacks, obesity and strokes— a third of them fared well. They stayed healthy, kept their jobs or found others quickly. It would be easy to assume these were the workers who'd grown up in peaceful, privileged circumstances. It would also be wrong. Many of those who did best as adults had had fairly tough childhoods. They had suffered no abuse or trauma but "maybe had fathers in the military and moved around a lot, or had parents who were alcoholics," says Maddi. "There was a lot of stress in their early lives, but their parents had convinced them that they were the hope of the family—that they would make everyone proud of them—and they had accepted that role. That led to their being very hardy people." Childhood stress, then, had been good for them—it had given them something to transcend.

I'm not a parent but it certainly makes me look at parents who try to take away stressors from a child's life. I'm reminded of the butterfly illustration that when a butterfly is trying to emerge from the cocoon if someone opens the hole and makes it easier for the butterfly to emerge, that the butterfly isn't able to fly. The work (stressor) of working through the hole, making the hole bigger, and rubbing it's wings against the hole does something that allows the butterfly to fly. Without that work, the butterfly is apparently just butter since it can't fly.