Quality and quantity were the only sex-related problems that came to mind?

Hmm? You quoted the rest of my question which talked about other things. It really was a question. :)

In any case, I must admit that unwanted pregnancies and venereal diseases (if these diseases have mostly become treatable then they're really not as much of a problem are they?) did not really spring to mind. I was thinking of effects on marriage and the impact through that on society at large.

However, even your data speaks only about a specific class of people, and not for all of America. Which suggests that certain socioeconomic groups can deal with the change in sexual norms while others can not. So the problem may not be entirely with the change in sexual norms?

Anyway, it is time for me to confess I am not American, nor familiar with the data trends on America and the effects of the sexual revolution there. I live in a country without too much sexual freedom and its own set of problems. It is interesting to see what problems are expected to happen when things get more laissez-faire around here though. And I wanted to point out the problems of a society with far lower sexual autonomy.

But this is tangential to Vladimir_M's point about some sort of double standards among liberals vis-a-vis sexual norms. For what its worth I don't consider autonomy as absolute and inviolable, and although I do place a high value on individual autonomy in sexual matters, I am not averse to a cost-benefit analysis either.

Since we're on the topic, I'll link one analysis that I'd found interesting:

the very tendencies which make adherence to traditional norms somewhat discomforting on an individual level are necessary in other contexts. Love is an inconvenience when it comes to arranging marriages for your offspring optimally on a social dimension, but it may be necessary for men and women to invest in their offspring due to the love they feel for them so that they live and flourish. In other words, psychological impulses which were inconvenient in one domain were necessary and adaptive on others. Phenotypically I’m implying that there was functional constraint, and genetically it would manifest as pleiotropy. I suspect that a strong tendency toward developing loving bonds with children is a much more important characteristic in these elite lineages than dampening the initial discomfort that may occur when one is paired off with someone with whom one is not particularly enamoured. In a social and biological evolutionary sense romantic love is less important than we might think in our individualist age. But, romantic love remains hard-wired within us because it is biologically impossible to suppress its manifestation so long as we need the emotion of love more importantly to bind us together with children.

Finally, let’s go back to Johnson’s treatment of the disjunction between idealized polyamory and realized polygyny in the ancient environment (at least to a mild extent). By this, he points to the reality that some of the Y chromosomal data point to a reproductive skew, where a few males tend to give rise to a disproportionate number in the next generation. In extreme polygyny you have a Genghis Khan situation, where males of one narrow lineage have an enormous reproductive advantage. The scenario sketched out in Johnson’s post is that females may have had relationships with several males (and the inverse), but there was a tendency toward favoring reproduction with one focal male or female. This does not seem to negate the reality of jealousy and drama. We see this among common chimpanzees, who have a classic mating system in the extreme sense outlined by Johnson (this species has huge testicles to generate viscous sperm the competition is so extreme). And modern polygamorists who have formal relationships all tell tales of enormous time investments necessary to maintain proper relationship equilibrium. This is I think the reason that elite lineages in mass agricultural societies turned toward simpler relationship networks. The older model was simply not sufficiently stable for the purposes of maintaining the social and cultural systems necessary for the proper functioning of the older Malthusian civilizations. This is evident when conflicts within elite lineages are often rooted in questions of paternity and maternity (half siblings; Charles Martel was the bastard son of his father, who superseded the legitimate line), or accusations of false paternity (the first Chinese Emperor was subject to this rumors due to his bad reputation in later generations).

From Gene Expression