Sure seems like correlation to me.
Older fathers are more likely to have established careers, establishing higher socioeconomic status, affording a lifestyle that engenders "geekiness".
Older fathers are more likely to have established careers, establishing higher socioeconomic status, affording a lifestyle that engenders "geekiness".
If someone has a "geekier" career path or educational background, they're almost certainly more likely to have geekier children.
I think that controlling for variables means that you've tried to reduce the impact of other variables on the two that you're interested in. From Wikipedia: "In statistics, controlling for a variable is the attempt to reduce the effect of confounding variables on an observational study. It means that when looking at the effect of one variable, all other variable predictors are held constant." [1]
If you could control for all other variables then you'd know how much of a connection between the two variables that you're looking at.
I think this doesn't guarantee causation, though - you'd need to do experiments where you adjust the independent variable and then verify that the dependent variable changes the way you're proposing it should.
At least, I think that's how it works. Anyone else want to chime in?
[1] https://en.wikipedia.org/wiki/Controlling_for_a_variable
You also have to assume that it's possible for every person/unit of study to have a non-zero probability of receiving either treatment for all levels of the variables you are controlling for in order for the effect you're estimating to be defined. That is more likely to be violated the more things you have to control for.
Controlling for variables can rule out alternative causal relationships (shared causes between A and B rather than A causes B) as explanation for correlation, but can't rule out coincidence. They strengthen the case for these plausibility of a causal explanation.
And, likewise, no similar effect was seen on daughters, either from older fathers or older mothers.
Or that it's a product of the socio-environmental factors discussed, but other socio-environmental factors like cultural gender roles mitigate it to undetectable levels in the mother » child and parent » daughter cases.
My completely unscientific impression is that scientific & mathematic acumen generates less of a financial return for women, and that when it does, it tends to generate a return earlier, with technical skills providing a foot in the door but subsequent success due to professional relationships. If, as I think the grandparent is suggesting, you posit that the reason for the observed correlation is that geekier males tend to be the ones that have children late in life (as opposed to earlier or not at all), then if geekiness in females leads to either no delay or not having children at all, you wouldn't observe the effect in females.
*This is not to say that women don't play sports with their sons, but to say that it's silly to assume that all young fathers play sports with their sons.
In families with older fathers, [assuming] there is a higher percentage of dual parenting ... which could mean more attention at home = less time playing sports with the neighborhood kids
True but I'd bet that many of these men came from urban areas where the community had services in place for younger people to find older mentors, and generally stay out of trouble.
I'm from eastern Kentucky originally and was lucky to have a fantastic stepfather, but I watched a lot of kids grow up with not much support past their single parent of either gender, and only a few of those I knew made it to 18 going anywhere near the correct trajectory. Outside of churches, there wasn't a lot of taxpayer-funded support for kids with single parents as it was probably a "moral" issue to the local politicians who still find the idea of a single parent family abhorrent and prefer to ignore it.
"In the study population, advancing paternal age was associated with increased risk of some psychiatric disorders (eg, autism..."
Meg Jay writes more about the practical implications of potentially delaying common life goals in "The Defining Decade"
https://www.goodreads.com/book/show/13523061-the-defining-de...
Their research is biased, and the entire organization follows a gay therapy model (which is to "teach" gay kids that their orientation is wrong).
"This effect persisted after controlling for parent's social/economic status, qualifications and employment."
[1] https://www.eurekalert.org/pub_releases/2017-06/kcl-odh06191...
Haven't read the original paper yet, so no opinion on quality of the reported research.
Russia is a tought life country. A decision to start a family when you are still in your prime may make more sense there.
> The mother's age had no impact, and daughters seemed to be immune.
When a significant effect is seen in only one of four comparisons (maternal vs paternal, sons vs daughter), then you have to suspect that the effect might be spurious.
My wife had our youngest daughter at 40 (I was 43), and my daughter was diagnosed as autistic at 3 and a half. After lots of therapy she was able to mainstream at age 8, and made the honor roll this year.
This morning she noticed a year in a book her older sister was reading. She exclaimed "That's the year Isaac Newton was born!". I said "okay" not sure if she could be right, and she then whispered to me, "and it's the year Galileo died". I looked it up, and she was right. So I kind of consider her geeky.
This is anecdotal evidence but one of my friends had a very old dad. He had issues which forced him to wear bifocals and hence he didn't participate in sports. And his father was 60 when he was conceived so his dad didn't play catch with him or get him to try out for little league or play basketball with him.
So instead, he stayed home mostly and used the computer and got into "geeky" stuff.
The father's other children he had when he was younger are all very active, athletic, etc and none of them have to wear bifocals, etc.
I got into sports because my dad played catch with me and encouraged me to play sports because my dad wasn't old when he had me.
On the one hand, older fathers will be more established, but on the other hand, they will have more defective genes and less active/physical.
So, it's a real issue, but it's also very was to percieved it as much bigger than it is.
To start, I'm going to assume that, by defective, you mean unintentional, correct me if I'm wrong. This is equivalent to the assertion that there is no feasible mechanism to preventing your germ cells from accumulating damage due to age, because otherwise, if it was maladapative, AND evolution could design a mechanism for preventing it, it would have. It's been long enough since mammals started reproducing sexually.
This doesn't even make a little bit of sense though. It's clearly possible to keep the error rate constant. What's the difference between the germ cells in my body and the germ cells in my offspring's body. Why do those last longer?
As you grow older, your offspring have more genetic diversity. It seems like the accumulation of mutations is intentional for older parents. The more similar your children are, the more likely they are to compete with each other, and the older you are, the more children you are already likely to have. So I propose that this is not a defect, but rather by design.
Second, why on earth does this explain the hypothesis? Nerds are smarter on average, yes? Does it not make at least twice as much sense that smarter individuals are sexually attractive at older ages than athletic ones than reasoning that genetic defects are the thing that makes a person smart.
Interesting question, I'm not sure but there is a selection mechanism with sperm creation, movement and implantation.
Ie your bad germline cells with too much damage don't make it to the next generation.
Why bother going to all that trouble when you can move the DNA to a new body and let the old one fall apart?
For it to have been worth it, a longer reproductive career has to pay off more than the opportunity cost of spending effort on other strategies eg aquiring more mates or investing more in your kids.
The most optimal balance is of course the DNA running around today.
https://www.scientificamerican.com/article/children-with-old...
"Effects of increased paternal age on sperm quality, reproductive outcome and associated epigenetic risks to offspring"
https://www.scientificamerican.com/article/children-with-old...
But in 99:100 cases the kids are as healthy as the ones of a 23 year old mother.
I don't have the exact numbers but it's something in that ballpark.
It's not a weak versus strong physical thing. And it would affect mental capacities at the same rate. Geeks are usually not dumber than average.
Everyone has a few mutations in protein coding regions, and the number rises with paternal age. Most mutations are neutral or harmful.
More rolls of the dice to accumulate more (likely small) damage is probably going to hurt you.
The way it almost certainly works is people who have better genes (for socioeconomic success in our current society) have kids later and these kids inherit these traits....
However it would probably be better if the dad had the kids younger.
It's also easier for denovo mutations to cause mental rather than physical problems as the brain is very complex so there's more genes used and more to go wrong.
PS I'm a 37 year old bioinformatician expecting a little geek in a few months :)