Comment by dahart | Hacker News Reader

Comment by dahart | Hacker News Reader

Parent Full thread

> Did you mean to say “intelligence is primarily genetic” instead? That I would agree with.

Perhaps I did mean to say child prodigies are evidence of the heritability of intelligence; that it suggests intelligence has a large, possibly majority, genetic component, if kids are outliers without much training.

Okay, so you’ve been objecting to ‘physical traits’ but agree with ‘genetic’… What is the difference in your mind between those? I see them as, broadly speaking, the same thing. Physical traits are phenotypes, no? Genetics is the biological component I’ve been talking about all along, and heritability is defined as that which is genetic, i.e., not explained by the environment or chance, i.e., not due to training.

Knitting, bull riding, and playing piano are neither intelligence, nor are they physical attributes. They are learned skills. It seems some people may have genes that may help them learn these skills faster than other people, but these are not ‘physical traits’ in any way shape or form, and your commentary on that term isn’t making sense to me right now. If you think piano playing is a ‘physical trait’, that could explain much of the miscommunication in this thread.

But musical skills are largely genetic. https://pmc.ncbi.nlm.nih.gov/articles/PMC4073543/

I still refuse to call playing piano a physical trait.

I must have misunderstood you above, we completely agree there; piano playing is not a physical trait.

We are finally getting somewhere, it’s too bad this got too deep before finding a basis for productive conversation. The paper you linked is very interesting, I would just note that your strong claim with the qualifier “largely” in your statement is not supported by the paper. The paper does not demonstrate musical skills are primarily or ‘largely’ genetic, it only suggests there may be some heritability of music perception. At least some of genes it mentions are nothing more than hearing anatomy, so of course they affect music, but they also affect basic speed and any audio. It’d be wise to not overstate what that paper is saying.

I could link to a bunch more studies that find more direct genetic links to musical aptitude in particular rather than musical perception in general. But I'd rather skip the busy work and jump straight to the point where we both agree to the following.

1. Musical talent is hereditary to a significant degree.

2. Musical talent is NOT a physical trait.

3. Therefore, being hereditary is not a proof of being a physical trait, despite the literal physical differences in DNA sequence.

Deal?

#1 is not a justifiable statement as written, #2 is true, #3 needs better terminology. Genetics does determine physical traits (physical traits are defined as phenotypes), heredity is about genetic variation. If you agree musical ability or intelligence are significantly genetic, then it follows that musical ability or intelligence must be attached to, associated with, or correlated with physical traits of some kind.

In light of your acceptance of intelligence having a significant genetic component, I wanted to re-evaluate the discussion from the top. You pushed back on my attempts to discuss genetics and made strong claims about training being important for intelligence, and now you’re making strong claims about genetics being important. I don’t know where that leaves us. My original point, recall, was that genetic variation doesn’t support the popular high-IQ narrative of so called super geniuses. Genetics cannot explain your claim of 100x difference in intelligence, and the only thing we’ve talked about that does explain it is training, which is not genetic, and, we both agree, boring.

There is a world of difference between "is a physical trait" and "is attached to, associated with, or correlated with physical traits". The way I see it, saying that intelligence is correlated with physical body features is admitting that intelligence is not a physical trait itself after all.

The first reason I insist on the difference is because absolutely everything indirectly depends on physicality of the biological body. Spirituality aside, there isn't a single thing about humans that doesn't depend on the shape or size or chemistry or electrical charge of something somewhere. This makes "physical trait" an utterly useless category, one that clearly includes playing piano, and I really don't like that.

The second reason I insist on the difference is because the correlation doesn't have to be linear. There's no reaso why it can't be quadratic or logarithmic or exponential or hyperbolic or whatever. Being a literal physical feature imposes normal distribution with tight variance. Merely being correlated does not. If you still want to argue geniuses are not that much more intelligent than average people, you'd need more evidence than simple hereditability.

When you say "intelligence is a physical trait", I hear "there is a part of parts of the brain that have a certain total volume/mass/density/number of neurons/synapses/neural pathways/etc., and that number is the literal definition of intelligence". It's how it works for every other thing that we call a physical trait. If you didn't mean it like that, maybe you should have used a different terminology from the get go.

Now excuse me while I go looking for 10-15 more citations on the genetic component of musical ability that you're definitely not going to dismiss as irrelevant for one reason or another.

It seems like you maybe missed the part in the middle of the thread where I said you’re right about IQ scores and what we call intelligence not being a so called physical trait. I’m not arguing that at this point and haven’t been for a while, because it became clear we are talking about different things. I’m looking for more mature terminology at this point, established phrases and concepts we can agree on, because this is too sloppy of a discussion. You’re making assumptions and jumping to a weird conclusion about what ‘physical traits’ means and I don’t agree that it’s useless, other than that the term has somewhat poisoned this discussion and is preventing progress. Physical traits are phenotypes, and phenotypes are an extremely useful notion in a discussion of genetics vs environment vs chance.

Your statement about correlation being an admission of not being a physical trait sounds naive to me; it’s ignoring the existence of polygenic traits.

Another source of terminology confusion here is the difference in what we mean by ‘intelligence’, and it’s probably way more important than what ‘physical attribute’ means. I really meant something different by ‘intelligence’ than you mean, and that’s my fault for not clarifying I was trying to focus on heritability and factor out learned skill.

I would love to see additional references about music and heredity, I’m looking forward to it.

You know you both have been locked in this unproductive 2-person thread for days now right?

It wasn't unproductive at all! Can't you see we just about worked out a consensus?

OK, ok, my bad, carry on! :)

Reply on news.ycombinator.com