This is a link to an article on cohabiting families and their impact on children.
It's sobering to note that pre-school children are 47.6 times more likely to die if in a cohabiting household than with married heterosexual parents. I have a suspicion that part of this may be that parenting requires a strong commitment to other persons,which heterosexual marriage gives, while cohabitation (and homosexual relations) are more associated with the indulgence of sexual whims. And, by the way, to the argument that allowing homosexual marriage might raise the pool of responsible parents, I note that in countries where it is legal (and criticism of it is proscribed as "hate speech"), such as Sweden, homosexual marriage is both rare and unstable.
Back in the 1960's, many in the counterculture advocated imitation of the sexual "spontaneity" of the African-American community--which then had an illegitimacy rate of roughly 23%, compared to the 75% today. A generation later, we have an increasing number of children at risk, phenomena such as the Frank Lombard case (in which a homosexual man allowed to adopt a child prostituted his five-year-old adopted son online), and an "acceptance" of alternative life-styles that truly kills. We are not in an evolving society, but one that seems determined to commit civilizational suicide