> However, another finding was completely unexpected: on Crete and the other Greek islands, as well as on the mainland, it was very common to marry one's first cousin 4,000 years ago.
I guess this is revealing is modern, western biases. Throughout much of history and through large parts of the world, it was very common for cousins to marry. Even in the Bible, Jacob marries his first cousins.
Inheritance to daughters and widows was developed and enforced by muslims, and I hear in turn families became motivated to marry among their own to keep the wealth in the family.
It depends on what era of the Catholic church we're talking about. The medieval church got very expansive about which relations were illegal to marry, including in-laws.
> until the 13th century, the church forbade marriages with consanguinity or affinity (kinship by marriage) to the seventh degree— a rule which covered a very large percentage of marriages.
So it would forbid you marrying your brother-in-law's first cousin, for example, even if you have no consanguinity with them. Even not counting affinity, you'd still be forbidden to marry third cousins, which nobody has had problems with for centuries.
The rules could be waived with a papal dispensation. Probably a big motivation for creating the rules, since that would mean that they would always have a significant number of royals who needed a favor.
I think that's why so many people have this unreasonable urge to travel. If you didn't have that in the past very little genetic diversity was available for your offspring.
> I think that's why so many people have this unreasonable urge to travel. If you didn't have that in the past very little genetic diversity was available for your offspring.
I'd say most of the reason is advertising. There's a lot of people making a lot of money due to everybody travelling around and buying stuff.
"I think that's why so many people have this unreasonable urge to travel."
It might also be, because most of human history, we have been (half) nomads and settling in one place for life, came much later. People went, were the food was, usually herds of animals. And women stealing seem to have been quite common, until recently (when encountering other tribes).
"The more difference, the better outcomes."
And I don't think one can generalize that, otherwise it might makes sense to try it with apes ..
I have the (maybe romantic) theory, that attractivness is no universal scale, but a sign of individual fitting (filtered out deep inside, mainly via biochemical processing aka smell). Meaning a person you fell in love on first sight, is probably a good match.
> I have the (maybe romantic) theory, that attractivness is no universal scale, but a sign of individual fitting (filtered out deep inside, mainly via biochemical processing aka smell). Meaning a person you fell in love on first sight, is probably a good match.
This seems like it must be at least partly true, but it's probably a complicated mix.
We are genetically programmed (via evolution) to find certain things attractive. This could easily mean that somewhere in that genetic programming something "knows" that offspring with that person would do well (or it could mean that the genetic programming is broken because it was trained in a different environment than currently exists--we now have a larger pool of potential mates than previous generations did, for instance).
There's also the possibility of green-beard type effects (eg a gene causes a perceptable trait and also a propensity to be attracted to that trait). That would mean that there's no real benefit to the organism to mating with someone attractive for that reason, there's only benefit to the gene that causes that.
But yeah, if I were hypothetically looking for someone to procreate with, I'd certainly look for someone who looks and smells attractive to me (though that's also just going to make the process more fun).
A lot of attractiveness is societal as well though, of course. We base what's attractive on what we see others attracted to, and on what we're sold. A lot of that is visual, so if you really want to trust your genes, smell might be the way to go.
"We base what's attractive on what we see others attracted to, and on what we're sold. A lot of that is visual"
Yes, with the model that attractivness is a universal scale from 1 to 10. Which is doing a lot of harm to teenage (and adult) minds. I think using filters for profile pictures to fit a certain unrealistic standard, has become quite normal. Leading to people constantly being unsatisfied with the way they really look.
> And I don't think one can generalize that, otherwise it might makes sense to try it with apes ..
Well... Of course I meant within a human species. Variety of human genomes is so small that it's miniscule when compared to gap between us and apes.
Two black humans from neighboring regions in Africa might be more genetically different from each other than European and Chinese person are.
Scientist estimate that at some point in human evolution there were only around 2000 humans left. We squeezed out of it 8bn now. Within our species we need every bit of diversity we can get.
> I have the (maybe romantic) theory, that attractivness is no universal scale, but a sign of individual fitting (filtered out deep inside, mainly via biochemical processing aka smell).
I agree that this is a factor. But I don't think you can deny that there's also generalized component of attractiveness that works on almost everybody regardless of their genetic makeup.
Of course some of it is just being attracted to health, youth and strengths but those are determined by genes to some degree.
It’s odd, because Islam preaches ‘bodily purity’ but repeated cousin marriage rapidly causes the accumulation of significant genetic defects - so you’d think religion would steer culture towards better beliefs and practices concerning that.
Yeah, my post was ambiguous - I was wondering why people who followed Islam retained a cultural practice which seems at odds with the religious principles of physical and ritual purity.
> so you’d think religion would steer culture towards better beliefs and practices concerning that.
If we were to take into account what would influence a family to practice marriage between cousins in excess (which is largely a preoccupation with material wealth and status), then it does.
I find it entertaining how much marriage rules have changed over the years, yet it seems to be a long-standing human practice that is not terribly sensitive to asymmetric risks or downsides. It seems no matter how unconscionable a contract it may look like on the surface for the wife or the husband (depending on when and where in history) it persists in widespread use.
https://www.nature.com/articles/s41559-022-01952-3