That This American Life episode was the first thing I thought about when I read this news. I heartily second the recommendation that everybody listen to it. It made me very happy that the NUMMI plant was going to get a new lease on life. I hope Tesla makes it.
The way that life expectancy works is that it was low because so many people died of disease in their youth that it dragged the average down. But people who lived to old age still lived to what we would consider an old age today. There would just be fewer people who lived that long, but not dramatically fewer.
There's a thing called Delayed Sleep Phase Sndrome. It's a circadian rhythm disorder that affects maybe 1/2 of 1% of people (but seems to be more prevalent among engineers and software people, possibly because DSPS sufferers choose vocations that allow for flexible schedules). Essentially, DSPS people have a natural sleep-wake cycle that's shifted a few hours from the norm. My natural cycle is to sleep at about 2:30am and wake at 11:30. I can force myself into a "normal" schedule, but I can't change my natural circadian rhythm, so I suffer from various effects of sleep disruption that are similar to jetlag. For some reason, a high proportion of teenagers, particularly boys, experience temporary DSPS during their adolescence. It can be as many as 20%. I suspect that the natural creeping of the circadian rhythm that happens during adolescence (as mentioned in this article) kicks into overdrive for some kids, and gives them DSPS-like symptoms during that time. Most of these kids grow out of it and re-establish a normal rhythm into adulthood. People like me, however, keep their DSPS throughout their lives. (And it's hereditary. I got it from my mother)
http://en.wikipedia.org/wiki/Delayed_sleep_phase_syndrome