I like to take the middle ground here, that yes, humans are biologically mammals, but unlike animals, that are mostly controlled by their biology, humans are able to go beyond our biological imperatives to do other things.
A superb example of this goes to the heart of the matter, with human reproductive strategy.
To start with, about halfway through gestation, the testes of the fetus of male mammals secretes a squirt of testosterone, which travels to the brain of the fetus, and tells it that it is a “male” fetus. If it does not get this squirt of testosterone, the brain is female, by default.
In the 1960s, and then again in the 1980s, scientists did extensive animal experiments with this one event, sometimes adding testosterone where there was none, other times blocking testosterone from reaching the fetal brain, and they even went so far as to provide testosterone to half the brain of a fetus, but not the other half.
In doing so, they created female animals that exhibited male mating behavior; male animals that exhibited female mating behavior; and bisexual animals that exhibited the mating behavior of both females and males.
My point is, that in animals, this is enough to determine sexuality. Heterosexual, homosexual, or bisexual.
But not in humans. Though medical conditions can result in feminine *behavior* in boys, and masculine *behavior* in girls, and even androgyny in both, it *does not* determine their sexuality.
Something in humans allows them to override their biological mating behavior, so whether they are heterosexual, homosexual, or bisexual, this major biological event does not dictate it, unlike all other mammals.
And that is just one thing. Humans have innovated other mating strategies that are unknown in the animal kingdom.
The strategy of basic biological reproduction is complex: for males, it is to provide their DNA to as many females as possible. For females, it is to get the best male DNA donor.
But more evolved species use monogamy to achieve a better outcome for their offspring, in which the male stays with a single female to provide for their offspring. This requires a compromise by both the male, to mate with just one instead of several females; and by the female, to get less than ideal DNA in exchange for help with provision.
However, humans have uniquely taken this further with the idea of socially-enforced marriage. The flaws in the animal system of monogamy are first, that if there is an abundance of males, those with the best DNA are not the same as those that are the best providers. Second, that while all animals are compelled to mate, many are not suitable for mating. Biologically they are intended to die without having reproduced.
Socially-enforced marriage overcomes these things by maximizing the reproductive bond, by putting the couple off limits to others, non-breeders. The entire affiliated group of humans protects couples from interlopers.
However, this also means that because non-breeders are still compelled to want to mate, there must be distractions to prevent their interference with a married couple. This might include things such as infertility, prostitution, or post-menopausal mating. The latter two confined at least to primates, if not unique to humans.
As an aside, periodically studies are made of chimpanzees, in which a single dominant male has a harem of females. However, just outside the perimeter of the dominant males territory are other males, seeking to lure members of his harem into mating with them.
Researchers like to use this as an example of the “normality” of cheating. Since chimpanzees do this, then it is okay for humans to cheat. However, they do not examine the complete picture.
If a dominant male catches one of his females mating with an interloper, he is likely to kill both of them. So, if cheating is okay because chimpanzees do it, then so is the homicide of a cheating spouse and their lover.
Hmmm… Yes. Well, your thinking is very unique regarding human uniqueness.
It should be noted that throughout human history dominant, powerful males have tended to have a great many more children. Either through formalized polygyny or informal philandering. Or, IOW, it is GOOD to be the King.
This has been reversed in recent decades, with high-status males (and females) much less likely to reproduce than low-status people.
The long-term consequences of this seemingly anti-Darwinian behavior remain to be determined. But it seems unlikely they will be positive.
True. Man cannot engage in mere animal sexuality without sinking beneath even the animals, who are innocent in their animality.
HERE: Sexual Secrets of the Normal
You wrote: "...However, humans have uniquely taken this further with the idea of socially-enforced marriage. ....Socially-enforced marriage overcomes these things by maximizing the reproductive bond,..."
And when did this forcing of the sexual genie into the marital bottle happen? :) See HERE
bttt