[tptacek]

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.

[dennis_jeeves2]

>You are using the word "heritable" as evidence for the "innateness" of a trait.

Hmm... not quite... ( 2 different things with overlaps, and remember I never used the term genetic)

>there's now substantial evidence in the other direction.

Links, please. ( would be surprised if it overturned all past observations)

[tptacek]

Before I do that, can you confirm for me what you believe "heritability" to mean?

[dennis_jeeves2]

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.

[tptacek]

Heritability is the ratio of genetic variance to phenotypical variance. How heritable do you think the number of fingers on your hand is?

[dennis_jeeves2]

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.

[tptacek]

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.