I'd like to look into the potential positives and negatives of a civilization with "eternal youth" ("very long youth" doesn't have quite the same ring to it). The information I've found so far leans heavily toward individual consequences. But I'd like to read more about the societal consequences. For example, what kind of psychological effect would it have? Political? Such a discovery would have an overwhelming impact, and I'm sure there are things I've missed.
If anyone would share an article or even a book title on the subject, I'd be very grateful!
ETA: These are all fantastically helpful! I will respond individually soon, but I wanted to quickly say thank you to everyone who's answered. So, thank you all very much!