i have all my tech stuff and finished all my puzzles but my ppl have been declining in life .. dont know how to keep them alive longer .. 80 is the oldest i have had .. help

Some will live longer then others. They could be getting sick as well, so make sure you have a doctor and that that skill is checked. Some jobs are prone to accidents (Research/building), and they can get injured do those jobs. The oldest villager I had was 102 and he was a master parent. (stress free job I guess J)