Since humans today seem inclined to lead promiscuous lives, is this evolution?
No, partner-selection and commitment is an acquired evolutionary trait that helps control disease among the population.
Or is it directly linked to a growing disrespect for the Bible?
Directly, no. Indirectly, maybe.
And how and why did marriage ever get to be so popular worldwide to begin with? The practice of marriage is observed among many cultures, even those that never had the Bible's influence in their society.
Basically, three reasons, disease control, child care, and protection of women.
For the first reason:
STDs aren't seen as that big of a deal today in Western cultures where treatment is common.
But historically??
STDs were
severe. They could cause your flesh to rot from your body and endure some sort of living hell. It's why I can't really find it within me to condemn ancient societies with harsh laws against adultery. Cheating on your partner was essentially
gambling with their life.
Marriage, by keeping people into small groups (either a man and a woman or a man and multiple women, considering for the vast majority of history there were more surviving women than men) with little-to-no outside sexual contact limits the spread of STD's, thus helping to stop epidemics.
It's one of those things we picked up without really understanding why we were doing it, like our aversion towards decay and rot. Marriage helps avoid disease.
It also helps guarantee paternity for a child. This allows a father to recognize "this is my child" and thus gives the father an incentive to care for and protect that child, thus dividing the workload of providing for and caring for the child.
Finally it provides a level of protection for women. Back in ancient times, when workplace fatalities were a
lot higher than they were today, a society benefited from having gender roles in the workforce. If men are the only ones allowed to the more dangerous jobs, then more women will survive. If more women survive, your next generation will be larger, and your society will out-compete societies
without these gender roles, because yours creates more people over time.
But, because of the higher risk, generally more risky jobs pay better. So to ensure that women can still profit off of the resources of the high-risk jobs while being insulated from the death those jobs can cause, marriage provides a system of pooled resources where a male with a high-risk high-earning job can pair up with a woman with a low-risk low-earning job.
Also of note, we probably had these societal gender roles before we even had people (Edit: REALLY bad choice of words, I meant "before we even were human", basically.).
And is marriage a bad thing? I mean, if humans are evolving without needing it; it apparently is the way modern culture is heading.
No, marriage is good for the three above reasons.
There is a bit of a problem though.
As technology has increased, so have workplace fatalities fallen dramatically. Workplace fatalities are
so low in the Western World, we don't really have a need for gender roles in the workplace, and so we have gotten rid of them. Women can do dangerous jobs without major societal consequences as those jobs have become so safe that female workplace deaths have negligible impact on reproduction.
So one of the three reasons marriage was good is no longer valid.
And STDs are not as big of a problem in the Western World, where methods of protection and treatments have been developed to combat this. STDs, of course, can still be life-ruining but nowhere near on the scale that older generations or modern third-world countries have to worry about it.
So one reason for marriage is no longer valid and one reason isn't
as important as it once was.
Which I believe is the reason that many people are now thinking marriage itself is unnecessary. Dangerous work is safer and promiscuity is also safer, and thus more people are interested in both of those things.
Though marriage still helps in dividing resources for child-rearing. Which leaves us with a bit of a problem, since it is shown that children who grow up in single-parent households, on
aggregate, have more problems than children who grow up with more than one adult in the home. (please note I stated on
aggregate. Of
course there are individuals with great single parents who turn out great or children with multiple terrible parents who turn out horribly, but when looking
in general on a trend...)
So I think that there's still that one
really good social reason for marriage, not to mention the fact that we've been evolving in marriage-oriented societies for thousands of years, and so psychologically, by this point, we might simply be geared for long-term committed partnership. I think the trend we see in people turning away from marriage is due to them noticing, whether unconsciously or consciously, that some of the old reasons for marriage are less valid, without noticing the one important reason left that makes it important.
