I don't think that controlling for variables can produce a conclusion of causation. (I'm posting half because I think this is correct, and half because I'd love to hear someone more knowledgeable about statistics confirm or deny this :) )
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?
Yes, you're right. To guarantee causation, you need to either directly manipulate the variable, or control for every other variable in the universe (impossible). The more extraneous variables you control for, though, the more evidence you have for causation.
Not true, you do not have to control for everything. You have to control for everything that may have an effect on both the treatment and the outcome. That implies you have to assume that everything you don't control for does not affect both the treatment and outcome, (though something can affect one). This assumption is not testable but sometimes reasonable.
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.
> I don't think that controlling for variables can produce a conclusion of causation.
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.
In my view, controlling for a variable X doesn't directly strenghten a causal claim, but allows to "rule out" another plausible explanation. In a way it shows that the observed effect is not accounted for, even if we take X into account, which means that it could be that the father's age influences filial geekiness. It could still be the case that another variable (that was not controlled for) accounts for the effect.
Curious what the correlation is between geekiness, length in career, and career success of women, and also how career success correlates with the age of parenthood.
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.
Or that it's a product of a Y-linked genetic trait.
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.
Or the he previous comment about lifestyle is applicable but only manifests itself for fathers as a result of society only recently starting to transition to women being able to be breadwinners.
Plenty of men with single mothers* learn to play sports just fine (see many NBA and NFL players).
*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.
> Plenty of men with single mothers* learn to play sports just fine (see many NBA and NFL players).
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.
that might be comparing two different things. In a single parent household (which I'm sure is heavily swayed towards single mothers) kids may be out playing with other kids.
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
I would not limit it to athleticism: men generally tend to lose "broism" and gain "wisdom" as they age. The relative levels of bravado and bookish authority that young boys could admire will therefore vary a lot with the age of the father. In addition to that, children calibrate their perception of normality to however their parents are. Many people believe that they don't want to be like their parents, but this normality calibration influences them nonetheless.
I remember a Stanford professor dived into this advanced age gamete suboptimality and stressed to everyone the compromises folks take in delaying past prime biological stages. He showed some time profiles of the diminishing chances for implantation, genetic disorders, etc. It was really palpable because you could sense he was a bit off balance having to present this sort of news to a bunch of young folks with the fountain of youth in their back pockets. The classmates were pretty much silent throughout the delivery. It got me to start thinking about biological optimum and I easily realized it was in the 20s as one would expect. All nighters were a piece of cake, probably to serve the care of an infant waking every 2 hours into the early hours of the night. Another piece of easily perceived evidence was the sheer force of the libido at that age and just how attractive women are in their peak. Lots of conspiring biology to contemplate teleologically.
At least in Russia, I observed an opposite with women. All women of my generation I knew who were into thing like engineering did settle down in early twenties.
Russia is a tought life country. A decision to start a family when you are still in your prime may make more sense there.
This could be down to older fathers having more basements, garages and tools. There are fewer degrees of freedom when you live in a drywall and carpet apartment.
Take caution. Extraordinary claims require extraordinary evidence.
> 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.
That's interesting, I thought there was a correlation between older mothers and autism, and autism has a correlation to geekiness.
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.
That could be true, but older fathers also have more defective genes, are less able to play with their children, etc. The children are just genetically "weaker", have more physical issues and participate in far less physical activity because their father is so old.
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.
Those are the rates for something like Down's syndrome. Gross chromosomal abnormalities are mostly determined by maternal age.
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 :)
Genetic mutations. As you get older, you accumulate more genetic damage, which can be passed on to children. It's fairly well-studied that children of older parents are more susceptible to genetic disorders.
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.
Naturally aborting a foetus due to genetic errors found in growth stagrs after combining with foreign DNA in your balls then shutting down the process and re-extract the germline cells is easy?
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.
I don't need to engineer the solution precisely, but the idea that it's impossible, or even difficult, to maintain the information degradation rate of mitosis, is clearly flawed. If your argument is that 'life has simply not found a way to do this yet', you should probably reconsider your argument.
My argument is that there are tradeoffs. There may be a way to do it but it has been thoroughly out competed by the make children and die strategy that dominates the planet.
But even at fairly old ages, the levels are very low. Yes, they are several multiples of the rates at younger ages, but the base rates are also very, very low.
So, it's a real issue, but it's also very was to percieved it as much bigger than it is.
First, the article throws out some very reasonable sounding things, like older dads are more established and stable parents. This seems totally legit.
Then they start talking of a 'geek gene' that gets passed down by dads as they get older? That seems ridiculous to me. We don't even know how general intelligence works on a genetic level.
Overall, I feel like we put way too much stock in genetics over how children are raised. The world children live in today (screens, different types of processed food, flashy movies and cartoons) is so different than hundreds or thousands of years ago. Early childhood years are also hugely important for brain development and social skills yet we give little kids screens to keep them quiet, hooking them early.
Just seems like any excuse to not involve parenting is in vogue now.
Almost every study on early childhood development and later outcomes shows that how a child is raised has very little to do with outcomes compared to heredity.
I looked at your links, but I'm still not sure I buy it. All of these seem to quote the same study, and it doesn't involve any child under 3, which is actually where a lot of early childhood development happens. That's the time when a child who's left alone in a room will basically turn into a vegetable.
I do agree that there's no magic formula for being a great parent. The baby Beethoven phenom, best color to paint your baby's room, etc are indeed useless. But that's good parents who actually care trying to read studies and be better. These parents are involved, and care. Not all parents are like that.
From your second article:
"In fact, the study found one key instance when parent time can be particularly harmful to children. That’s when parents, mothers in particular, are stressed, sleep-deprived, guilty and anxious."
This sounds like exactly the kind of thing that would happen less with older, more established parents.
On the other hand, if the parents can't hold a job, or are addicted to drugs, I think you'd be hard pressed to say that doesn't have an effect on childhood outcomes. If anything, parents who are criminals are more likely to have children that are criminals.
If you want to say criminality is genetic, that's a fair argument. But I believe it's more likely to be about class/race/means, and is a set of learned behaviors.
I think there's a limit to how good parenting can affect outcomes to the positive (genetics). But I also think bad parenting can't be ruled out. And none of these studies talk about sub-par parenting.
Then they start talking of a 'geek gene' that gets passed down by dads as they get older? That seems ridiculous to me. We don't even know how general intelligence works on a genetic level.
That's a bit silly. Far more plausible is the supposition I will make here: geeky guys are less likely to be teenage fathers and geekiness is generally heritable. There, no epigenetic assumption necessary.
heritable - able to be inherited, in particular.
inheritable - capable of being inherited.
Inflammable means flammable? What a country.
Sure you can inherit behaviors, but I'm trying to be specific and say I don't believe it's genetically inherited, but a behavior that is learned. Kids learn by mimicking.
We learned about hereditary traits long before gene sequencing even existed. You do not need to know how something works on a genetic level to make strong conclusions about heritability.
That being said, this specific case looks like bad reporting about a tepid study, so I wouldn't be surprised if it were totally wrong.
I read an article a couple of months ago about autism being linked to delayed fatherhood: http://www.nature.com/news/fathers-bequeath-more-mutations-a.... Being different was something that touched near and dear to my heart like many self-conscious geeks and my old man didn't have me until he was 41.
I know N=1... but when you're debating with your friends whether or not this (http://imgur.com/m52Wo4a) can be classified as a sandwich or if it warrants a new nomenclature entirely and realizing that these are the people you are associating with it's difficult to not look for answers.
There are several points of contention but here are some of the most common points I've encountered:
- When the term 'sandwich' is used in reference to a bagel being used for the 'bread' there is a presumption that the bagel is sliced along a transverse equatorial plane with the hole of the bagel being orthogonal to the ground. This photo clearly defies that convention.
- A sandwich by most conventions is kept between two or more slices of bread in layers. If there are more than two layers between bread in a sandwich they are stacked vertically and separated by individual slices of bread. The subject under discussion has two layers, which is conventionally acceptable for a sandwich to have, but they are not stacked vertically. Some scholars have argued that this means that it is incorrect to call this a 'sandwich' in the singular sense but it is acceptable to call the entity a composition of 'sandwiches'.
This is just a taste of the great bagel debate currently raging across very small niches of geeks but hopefully it gives you a flavour of why no definitive answer has been accepted by the community. And this has not even touched on the bagel-complete problems such as the topological properties of the mobius bagel http://images.tastespotting.com/uploads/thumbnail/125155.jpg.
Other mood and psychological disorders are linked to father's age as well. Turns out sperm and eggs are delicate and after 40 years of aging, simply can't do their jobs well. Evolution's mechanisms aren't kind to older parents.
The study seems to hint at the idea that autism spectrum at the very mild side might be "geeky":
>She added that some of the genes that contribute to geekiness and academic success might also lead to a higher risk of autism when a child inherits more of them.
I don't see a link to this actual study, only the TEDS study (was it actually parts of the TEDS study, or just using the same data?) But my first question is if they've considered if really the correlation is coming from closely related variables other than just age:
- Father's who start a family later vs father's who start a family early but have additional children later.
- Children who are more likely to have multiple older siblings.
Why is it obvious? Doesn't seem obvious to me. Is it because of the stereotype that geekier men don't hook up as young as non-geek men? What is the difference between a geekier man and a less-geeky man? Can it be objectively defined?
I'd suggest that geeky dads are going to attempt to be very logical with their all their decisions. So they might take their time with their spouse, want to get a house, get finances in a great place, etc, before making the jump to have kids.
At some point the geekier types either alleviate all their concerns and/or realize that a lot of great things can't be framed into a logical decision, and they make the jump. :)
It's logical from a financial perspective for many people. When I think of older first time parents I think 30+. In the past upper 20s might be considered older because people would get married in young 20s and have children shortly after.
You want to be able to afford the increasingly higher costs of having children. You want your marriage to not be stressed from added financial responsibility. People tend to make more as they get older so many wait. That played a role in my decision to wait for sure.
The physical component you suggested is certainly a logical argument for having them younger. That pressure is higher for women too because they consider the risks of pregnancy (as you noted) and the possibility they may not be able to conceive if they wait too long.
I understand your decision but to me - having a kid at 30 over the physical concern is not logical. Sure I'd be 48 when they're 18 but even at that point, I don't have physical concerns. In fact, that would provide additional motivation to remain healthy. If I was considering physical capability for grandkids then that might enter my decision. My wife just talks about how we'd be the older parents in our kid's class which doesn't concern me.
Everyone's situation is different though. I just think finances is a big driver for those that wait and honestly I think it's a good one. If you're married and don't have your finances in order, there's a good chance your marriage won't last and you'll rack up more stress which isn't good for you or your kids.
> How is it logical then to wait until you're older (define older!)?
There is more than one variable at work. My parents had me at 19. I remember the family always struggling so I decided never to have kids until I was 30 (and later just turned into never).
"Geeky" is the wrong word to use here. Educated people with ""good"" jobs have children later - geeks that work in software/STEM/medicine are included.
Plenty of my non-geek friends with good income careers are just now trying to settle down at 30.
Geekiness implies social outsider status almost by definition. Plus the rational argument for contraception and family planning seems more likely to be internalized by people who have a reputation for rationalism.
This is kind of alluded to in the article, but isn't their definition of 'geekiness' just a definition of the difference between older fathers and younger fathers? As you age your ability to focus on a single task increase, your become more aloof, etc.
What about epigenetic factors in low stress environments? We already know this is proven to be a huge factor in gene expression. That is probably the "stable" part they mentioned.
Maybe its not so much the Dad; its having older siblings by the time you're Dad is old? My youngest grew up very mature, trying to keep up with his older brothers.
My first son is a soldier. The 2nd and 3rd are software developers and musicians. Works for me.
The findings seem a little off to me. My father was 26 when I was born and he was a leather cutter, so our family wasn't advantaged in any way. He was also a hopeless parent and played very little part in my personal development, despite being physically present throughout my childhood.
The really key environmental factors that led me to being a geek can firmly be put down to: My Mother taking me to the library every week; having plenty of books at home and school; and good quality teaching at school. I can't imagine that having an older/wealthier father would have that much additional impact on top of these factors.
“I don't fit the pattern” is not a strong reason for rejecting research findings that claim an increased probability of an outcome based on an input, not an sine qua non relationship.
Precisely. I even fit the pattern, being an aspergers STEM major whose father was in his 50s when I was born. But that's no more evidence than the other person's refutation, because personal experience is worthless here. Statistics matter, and our own biases serve only to cloud our analysis.
They are a little off because you compare them to your own individual life and you ignore the general trends.
I'm a geek and libraries had nothing to do with. Rather it was all about my geek big brother and some of my geek friends. Yet I don't deny that the geekiness can be inherited from an old geek father in most cases.
I think it would've been more convincing, if the study was able to show the splits down non-/geekie parents (or by parent's occupation). My dad's an engineer and he's very geekie for his generation, growing up I always wanted to be like my dad. When I was 12, I'm sure I would've scored high on the geekiness index.
My sons are both geeky (love science, minecraft and math) and like to skateboard, BMX, BayBlade, shoot each other with nerf guns, fight all the time and just play whenever they can get to it.
I was 36 when I got my oldest and 39 when i got my second son.
Interesting, but this article doesn't say actual numbers for how old an "older father" is defined in the study, and I'm too lazy to dive deeper. Anyone else find out?
Basically if you spend all day with your nose in a book, your eyes start going to pot. And the people most likely to read all the time tend to also be quite smart.
Makes sense, older fathers would be more aware of how technology changes the word and how necessary having at least an understanding of tech is to their offspring's future success.
Assuming we're all talking solely tech-geek then I'd posit that older fathers are going to be more out of touch with modern tech; which doesn't show anything in itself.
The might however have more disposable cash, did they control for wealth?
Older fathers are more likely to have established careers, establishing higher socioeconomic status, affording a lifestyle that engenders "geekiness".