Has the spacing between generations lengthened in the Star Trek universe?

Question

Reading this question I was struck by an underlying assumption present in some answers that generational length (~25 years) would remain about the same. But the thing is, that may not be the case. In our world, the best time (biologically speaking) for us to have children is fairly young, while the best time for us (psychologically and economically speaking) to have children is significantly older. Having children later increases likelihoods of various complications, genetic disorders, etc.

But in Star Trek, we have two fundamental differences in play. One is advancement of medical technology such that we can assume age of the parent is no longer a limiting factor. The other is economic changes which mean it is no longer more stable to have a child later in life. The limiting factors are therefore when you feel like having a child and what you want to do with your life, what sort of career and personal development you want to have before you have a child. Picard's brother, for example, is clearly a somewhat older gentleman but with a young son. On the other hand, his ambitions were relatively simple- he wanted to run the family vineyard.

So, obviously there are going to be those who want to be a parent early and often. But do we have any sort of commentary about time between generations lengthening in general in the Star Trek universe? Or, alternately, anything to show that the average generational length has remained more or less the same?

Answer 1

Perhaps it has a bit

If we assume, as stated in the question, that a generation is 25 years (perhaps even 30 or so), we might see some evidence that generations have increased in length somewhat by the time of the 24th century.

One of the best examples of this is the O'Briens. We know Molly was born in 2368 (Source). We also know that Miles was 40 then (he was born in 2328 [Source]). We don't actually know how old Keiko is, but let's assume she's a similar age to Miles. So that's a 40-year gap right there. Another interesting aspect about Keiko that is brought up on Memory Alpha is the following:

It's also interesting to note that Keiko's mother was apparently around the age of 60 when she had Keiko (assuming Keiko was not much older than 40 in 2369).

(Source)

Considering the age of Miles, the assumption is quite reasonable. Now, it would be quite unusual by today's standards for a woman to give birth at the age of 60. That's a 60 year gap in the generations there.

The only other major character with a child I can think of off the top of my head is Dr Crusher. Now, she was born in 2324 (Source), whilst Wesley was born in 2348 (Source). This makes Beverly 24 when she had Wesley, which fits in with current ideas of what a generation is.

The other important factor to take into consideration is average lifespan. In the 22nd century, 100 years was the expected lifespan (Source). It's not so farfetched so expect that by the 24th century this might have increased a bit (we see Bones aged 137 in 'Encounter at Farpoint Pt 2').

So, in light of all this, I would conclude that perhaps, the 'age' of a generation has increased somewhat by the 24th century. As people are living longer, the age they can no longer biologically have offspring becomes older, allowing for a given generation to be longer.