Unfortunately, no conclusions, just speculations in this article:

Last week, a study appeared in PLoS ONE, the peer-reviewed journal published by the Public Library of Science, that drew attention in Israel but made barely a ripple here: That men who’d survived the Holocaust lived longer — significantly longer — than their peers who'd never been under Nazi oppression. ... And so the obvious question arises: Why has one of the most traumatized populations in the world led longer lives?

...

The authors offer two theories. The first is the phenomenon of “post-traumatic growth.” It’s an intriguing idea, first developed by a pair of psychologists at the University of North Carolina, which stipulates that many survivors of horrific events emerge with a renewed sense of purpose and meaning, a reorientation toward life.

...

There’s another possibility, too, however. It's possible that those who were strong enough to survive the concentration camps (or many years in hiding—it's impossible to know how the study's subjects spent the war years) were bound to live longer. And the authors do float this idea:

"An alternative interpretation would be differential mortality, meaning that those vulnerable to life-threatening conditions had an increased risk to die during the Holocaust. Holocaust survivors by definition survived severe trauma, and this may be related to their specific genetic, temperamental, physical, or psychological make-up that enabled them to survive during the Holocaust and predisposed them to reach a relatively old age."

Here's the story of survivor Henri Landwirth who became a beloved philanthropist.

Great video, Geege.

Matt, I believe both explanations.

Those who survived WANT to live longer to spread their stories and understanding.

Those who survived CAN live longer because they needed strength and willpower to survive.

Thank you for posting this article.

It's interesting too that, in agriculture, plants that produce the greatest quality and quantity of Resveratrol (a reputed organic chemical agent that produces biological longevity) are found in those plants that are often the most severely and acutely stressed.  A well known example is that of the red grape vines of Sardinia, which have been shown to contain the highest concentrations of resveratrol, largely attributed to those vines being exposed to wild-gusting, spontaneous mistrals and hot Mediterranean sun.

Yes, we can argue that some acute stresses are biologically proven to have longevity merits.  But I still wouldn't want to undergo what those Holocaust survivors did just to gain a few years tacked on to my end of days.