1. There is no "grand order" to things as you think exists.
2. EVERY Homo sapien CANNOT reproduce (unless aided). It is only through our modern technology that infant mortality rates are low and that many who, without the usage of technology, would never have a chance at being pregnant. Most mothers would never survive Child birth and if they did, they would have even a higher chance of miscarriage or infant death. Also consider Some Homo Sapiens are and were genetically hard-wired to be hunters or gatherers and not gene replicators.
3. There is a genetic component in almost everything but that does NOT mean you can`t reverse it or change it. We are not beholden to our "selfish genes" in any way. Just as we can use technology to overcome genetic limitations, we can easily use forethought to choose not to have children. Furthermore, our cultural norms and values and vain desires can also dictate if we replicate. (this is the case for nearly ALL pregnancies.All one has to do is read this very thread on why they are having children) Human civilization may not have made it this far had we behaved or solely acted according to or on our genetic desires.
3. As Steven Pinker says on choosing to be childless-"I am happy to be that way, and if my genes don't like it, they can go jump in the lake."
4. Don`t fool yourself into thinking that your own bias of wanting or raising children is universal and that we all should expect or want children. If your posts are any indicator of your own intentions, then you clearly want children solely out of vanity as you seem to think some pittance of genetic immortality will carry on when in truth you probably have no advantageous mutation whatsoever to contribute to the wide and existing gene pool. The gene pool is so large with so few pressures that any contribution you did make (which is most likely none given the ENTIRELY SMALL amount of likely positive mutations that would arise each generation if any) would be nearly invisible.
I ve never heard of people in ther 50s who are "happy" not to have had kids. Also let's not forget that often not being able to have kids is linked to not being able to have stable relationships with women in the first place. And let's not also forget the fact the desire to have kids develops itself when you re living with a partner.
The desire/pulsion to have kids is biological first and foremost.
Developing the idea thru your life that you dont need to have kids is a societal, environmental construct that might interferes with the biological pulsion.
Progresses of sicence, technology, led to the spread of hedonism, indivualistic and materialistic behaviors. Richer social classes are more prone to be conditionned by hedonism, indivualistic and materialistic behaviors. Poorer social classes -especially from the third world, blacks, asian, arabs- often have stronger family oriented feelings than westerners.
Westerners - whites and blacks- are the only ones who are materialistic, hedonists, individualistic, AND WHO ARE DESTROYING THEIR FAMILIES TIES all by themselves.
Most asians and arabs once they have an access to an improved material life dont become extreme hedonists, dont become more individual, they very often marry/mix/balance strong family ties with the access to an improved material life. These are of course the main trends I ve seen from my own experience.
I also have read several testimonies of men and women in their 50/60s who never had children and are truly desperate about it and consider themselves as abnormal, unfulfilled. They say they spent most of their life trying to rationalize their desire not to have kids, just to figure that they still biolgogically -not intelectually- feel the need to have them. It means that whatever you do or think, you cannot supress the biological desire which is mostly chemically stimulated.
But that's just my own honest opinion.
Ps: Helen Fisher in "why we love" says " the general consensus amongst current top scientists at the moment is that about 50% of our temperament is inherited genetically, the rest is molded by education and our familiy/friend circles."
