Kylosophy

[Mike]

Then we would learn quite a lot from this very singular case study about the expression of neanderthal DNA. It would be a fascinating first look at a living example of a different species/sub-species of hominid.

[Mike]

Something a little lighter:

How would humanity change if all humans’ life expectancy was significantly increased (let’s say to around 500 years)? Would we think differently about climate change? Retirement?

[Eliahad]

Does this assume that our natural aging would be extended in a similar fashion? Would we still be an adolescent until age 90 or so?

[Mike]

No. Humans would still mature at the same rate they do today up until adulthood, and then we have processes (supposedly) to slow the deterioration of mind and body that come with old age.

Although, in answering the original question, a much longer lifespan might lead people to allow a longer period of transition between adolescence and adulthood. Maybe it becomes even more common for people to live with their families until well into their 20's or 30's or even longer, without the stigma that is attached to that today.