My thinking was that since I obivously like anyone I decide to have children with and since the child's genes will be a mix of ours and the child is more likley to carry similar memes than a random one it serves my other values to adpot and promote "having children until indefinite lifespans or cryorevival are available" as a value.
However my adopting "having children" as a value hasn't yet resulted in me having any children.
Unfortunately I have a feeling that the loss of ability to consistently use contraception is much more robust than a positive desire to not use it when optimal, evolutionary speaking and that in the long run we can't really run away from this as long as agents keep replicating.
So I found this post quite interesting:
http://www.gnxp.com/blog/2009/03/gnxp-readers-do-not-breed.php
(I'm quite sure that the demographics of this site closely parallel the demographics on Gene Expression).
Research seems to indicate that people are happiest when they're married, but that each child imposes a net decrease in happiness (parents in fact, enjoy a boost in happiness once their children leave the house). It's possible, of course, that adult children may be pleasurable to interact with, but it seems that in many cases, the parents want to interact with the children more than the children want to interact with the parent (although daughters generally seem more interactive with their parents).
So how do you think being child-free relates to rationality/happiness? Of course, Bryan Caplan (who is pro-natalist) cites research (from Judith Rich Harris) saying that parents really have less influence over their children than they think they have (so it's a good idea for parents to spend less effort in trying to "mold" their children, since their efforts will inevitably result in much frustration). And in fact, if parents did this, it's possible that they may beat the average.
(This doesn't convince me in my specific case, however, and I'm still committed to not having children).