Hey, Milo, good to see you here!
I was wondering what you might think of a speculation I have, given personal experience and some evolutionary biology I've studied.
Human smell is largely subconscious but highly acute nonetheless. A woman who has just given birth a few hours ago can more accurately identify which baby is her own among others by smelling a piece of clothing they've worn than by looking at them, for instance.
Likewise, genetic compatibility of a potential mate is more accurately predicted by smell than by any other means.
What is known colloquially as "chemistry" is largely down to smell. This is why people sometimes fall hard and fast online or even in person, and then when it's time for that first kiss, they're suddenly, "hmmm, this just doesn't feel right. There's no chemistry." The first kiss is the first time, given how often we bathe and how much scent we tend to use, that you get your first good whiff of the other person.
When women are not pregnant, they strongly prefer the smells of genetically compatible males. When women are pregnant, that changes, and suddenly they strongly prefer the smells of males who are closely related to them--fathers, brothers, sons.
Now. Given all of that, I was very interested to read an article on "sexual chemistry" that quoted a marriage counsellor as saying: "You'd be amazed at how many couples I've seen who've been married for 10 or 15 years, and all of a sudden the wife is complaining, 'I just can't stand the way he smells.'"
This is very much my own experience with my ex. I got my tubes tied after three kids, and all of a sudden he smelled like gamey pork to me.
We have seen a marked increase in heritable disorders and conditions over the last 40 or 50 years: allergies, asthma, auto-immune disorders, ADHD, autism (is it weird that they're all "A" words?).
Two of my three kids were hyperlexic--super-early readers but very late talkers, and have completely atypical social development and skills that sometimes get misdiagnosed as autism. I mean, they've gotten by and have mostly grown out of the most handicapping aspects of hyperlexia, but they're still weird as fuck. When I looked at the indicators for hyperlexia, they're traits that are overrepresented on my side of the family and their father's.
Do you think that because hormonal birth control partially mimics the hormonal state of pregnancy (you're already pregnant, so don't release another egg), that maybe this increase in these heritable disorders and conditions, as well as the seeming epidemic of divorces that occur round about the time when women have had their children and are going off the pill, might be due to how the pill disrupts women's ability to detect the genetic compatibility of a given male through "sexual chemistry"?