Sure people have a myriad of views on how family works, but that's the frame of law.
For instance if you raised a kid for 15 years, divorce for unrelated reasons (ex: repetitive adultery), but take the opportunity to have paternity checked, are you less of a parent of this kid than his biological father ? I'd suppose there's a variety of answers depending on each one's walk of life.
I'm not a big fan either, but that's how it is for now...
Too late to edit, damn it
Why? If you have doubts, then the DNA test will be ordered in the divorce proceedings.
Maybe you want to figure out if the child is genetically yours before you initiate divorce.
> consensual activity
> all parties involved consent
Well that's the crux of it, indeed. Most private testing is not done in a consensual way because that would require the assent of the child, which is likely minor, meaning it requires the assent of both its legal parents. If you have the assent of both the father and mother, it's easy (and free) to ask a court to allow the testing.
Paternity is clearly and demonstrably a biological concept. You can easily see this when pondering the idea of having sex with your parent, and the possibility of amplifying congenital birth defects. Note that if a child is misled about his or her biological father, the probability of incest increases.
Be that as it may, paternity is one of the most important and impactful relationship humans have, many social rules, taboos and rituals have evolved around it, marriage being one.
Paternity is a social construct.
There are cultures where paternity simply is not important. In a matriachal society, a person's mother's brother is apt to be more important than a biological father, sometime to the point of not knowing who the father is (because it is unimportant).
https://www.spiegel.de/international/zeitgeist/the-mosuo-mat...
The fact that most notions of paternity are almost universal means that there is something fundamental driving this which can only be overridden in a handful of cultures. Perhaps there is some instinctual male drive to be more invested in their genetic offspring. Investing in their own genetic offspring increases their biological fitness and makes them more likely to pass on their traits of favoritism. Perhaps in cultures that don't have these widely held traditions around paternity aren't able to secure paternal investment and encourage long term monogamous relationships, which leads to the culture's destruction, degeneration, or stagnation.
as well as a social construct.
This is slightly misleading since the basic biological facts of reproduction have not been modifiable so far in human history. Reproduction has always needed a fertile man and a fertile women having sexual intercourse. (Note this may change in the future with technological advancement, e.g. cloning and artificial wombs.) In contrast, the social aspects of reproduction have been varying a great deal on the surface.
I'd rather say that the social rules, rituals, taboos, institutions, all emerge and stabilise in order to give structure to and make predictable the underlying biological facts of reproduction. Note that reproduction is humanity's the single most important task.
Giving predictable, teachable and learnable social structure to reproduction has been all the more important before humanity started worked out how reproduction works and began to be able to control it at will (genetics, contraception etc). It is not surprising that there is a great deal of surface variety of social overgrowth on top of the basal biology, since genetics is rather complicated (and not fully understood as of June 2019, e.g. epigenetics) and has a lot of randomness built in. Moreover, reproduction, being the single most important task of humanity, intersects with all manner of other social institutions. This has encouraged the ad-hoc theorising, and overfitting on anecdotes that became enshrined as social institutions.
Summary: the social aspects of reproduction have been humanity's attempts to understand, manage and control reproduction, and are a reaction to the biological complexities of reproduction.
Royal intermarriage has been practiced by ruling dynasties since times immemorial. It had often been observed that this leads to problems and infertility, and indeed this is the root cause for the incest taboos that you find in varying forms and shapes in most cultures and religions. However, it has only been with the rise of modern biology and genetics in the 20th century, that this practice was abandoned.
Speaking of Ancient Rome, it has been speculated that the decline of the Roman Empire was in parts caused by the failure of the ruling families to produce enough children. Naturally, we don't have enough information today to confirm or disprove such speculation.
I have no idea why you link to an article about the Mosuo. It has no bearing on the biological nature of paternity.
It would be very interesting if we defined the concept of parents as being the adults with closest social link with the child. The idea of child support as being something imposed would then go away, as child support is generally only contested in the case when the adult have no social link with the child and thus no involvement beyond paying the bill.
It would also make same-sex relations identical to other relations as the law would not care about which adults have closest social link with the child. Marriage vs Cohabitation would also be a area which the law could ignore, and the concept of society taking care of children in need would become natural as there will always be two adults that is the closest social link, even if some of those are paid by the state.
The current system has a lot of costs and drawbacks. Using the marriage as the norm has caused a lot of issue here in Sweden and the system is currently being tweaked every year to account for a changing culture. 1/3 of couples with children live as cohabitation rather than registered/marriage. Family law has to keep up. Same-sex families with children is an other area which is growing and the law has seen updated several times the last 10 years.
Rather than having laws getting tweaked and warped each year to account for a changing culture, maybe it is time to address it from a different perspective. If a child treat the adults around them as their parents, the adult treat the child as their child, and social environment around them treat the adults as the parents of the child, then why not also have the law treat them as the parents of the child? Outside of medicine does the DNA then really matter?