Yes, it is innate, with a high degree of heritability. No one questions physical traits are innate, but some how when it comes to IQ it become highly contested...
You are using the word "heritable" as evidence for the "innateness" of a trait. "Innate" can mean multiple things, but the implication here is that it implies genetic determinism. Heritability statistics do not establish genetic determinism and, for intelligence, there's now substantial evidence in the other direction.
Heritability: Black kid born to black parents. The blackness is heritable
Innate: Albino kid born to black parents ( mutation, etc..) So here Albinism is innate to kid but not inherited.
That's a black and white definition ( for the sake of conversation). There can be intermediate states. For example even if the kid's skin is black there can be variation in skin tone, so slight mutation, but still largely inherited.
Anyway to answer your question the number of fingers in one's hand would be nearly 100% inheritable. A more accurate figure would be 99.<something>
tptacek , I'm not sure why you are hung up so much on the specifics, haven't we veer well past the main topic? My getting the definition of heritability, innateness etc. in this should not matter beyond a certain point. I understand that if we were experts debating a certain tropic definitions matter. Quirks , physical trait, depression, mental illnesses, and by extension IQ would run in families, this was common knowledge in the pre-modern era. ( and probably is still so in many parts of the an on urbanized world). Ofcourse one has to separate out the external factors like common food habits (that was common to these families) would impact psychological traits.
No, it is the opposite: the number of fingers on your hand has virtually zero heritability. Variation in the number of fingers on your hand is virtually always a result of environmental influences (for instance: thalidomide during gestation).
If you don't understand what heritability means, (a) you shouldn't be using it to make points about the connections between phenotypical groups of people and their measured IQ, and (b) the links I have for you aren't going to do you any good.
Fair enough. I that case I don't understand what the formal definition of heritability. ( I could some time and understand it but that beside the point)
So what term would you use to describe individuals inheriting trait from their parents eg, skin color ? especially the colloquial term.
The technical definition matters because the evidence people supply about the genetics of intelligence is based on that technical definition, not your intuitive definition. You said intelligence has been shown to be heritable. Indeed, it has. But that doesn't mean what you think it meant.
Again, fair enough.
( I'm pretty sure that when I used the word heritable first, the person understood it, although he/she may not have agreed with me.)
And if I may defend myself most terms with a formal definition start out being used colloquially and later if/when adapted scientifically may have a more nuanced definition. And after it is adapted scientifically the word continues being used colloquially. Isn't it generally assumed that when 2 people talk the colloquial is assumed? Unless they both decided to use the formal definition, or they are both experts in the subjects.
I don't think you should feel bad for using heritability in its colloquial sense. I'm just saying that you won't be able to support the claim you made with the evidence you had available. That's how discussions work: you make claims, some of them hold up, some of them don't.
Trying to quantify genetics and intelligence is fraught because of history and ethics. We cannot put one twin in a box of food and water and the other in schools of varying quality. We also cannot clone Einstein and put them in various schools then test them.
Everyone has to live and grow within unjust societies. Some groups will suffer from racism, others may benefit. So it's going to be hard to prove much of anything without a lot of twins and decades of natural experiments.
The eugenics movements and Nazi experiments have also made the whole subject taboo.
Finally IQ is quite arbitrary and the tests evolve over time too.
>The eugenics movements and Nazi experiments have also made the whole subject taboo.
I know this.
>Finally IQ is quite arbitrary and the tests evolve over time too.
The IQ test may be flawed, but is the concept flawed?
Can you see any downside in not acknowledging differing intelligence among individuals?
(we know the downside of acknowledging it - right from the Natzis, to individuals who may not try hard enough to achieve something)
And oh well - there are both twin studying and studies on kid adopted by their non-biological parent. Given the taboo, it may not be easy to find them.
You are arguing that low intelligence is innate, unchangeable. Which sounds very much like saying stupidity is genetic.