But reality says that beauty is correlated with fitness, which is correlated with intelligence. Beautiful people should tend to be smart.
That is a surprising mistake to make in reasoning. Did you somehow get the causality arrows reversed in your mind when writing this? Temporarily imagine that fitness was causing brains and beauty, rather than the other way around?
I think there is some positive beauty/intelligence correlation.
Quite possibly true. But surely not for the reason you suggested above.
Isn’t beauty a set of built-in fitness testing heuristics?
As far as I can tell, beauty is a combination of health heuristics and status markers which are developed in particular societies—some of the status markers are about rarity and others are about costly signals.
That is a surprising mistake to make in reasoning. Did you somehow get the causality arrows reversed in your mind when writing this?
There are no causality arrows in my reasoning.
Perhaps you think that by “fitness” I meant evolutionary fitness, and that both beauty and intelligence cause fitness. But by “fitness” I meant health. Sorry, poor choice of words.
Fitness meaning health. That works. But I think that your model does involve causality—from health to both beauty and intelligence. And, of course then beauty and intelligence will be correlated. I apologize for not anticipating that possible meaning. Since you post about evolutionary theory so often, that denotation of “fitness” never entered my mind.
With correlations it isn’t necessarily clear which way the causality arrows are pointing—or even if they run between the correlated items at all. In this case, one of the most obvious way to draw the arrows is from genes to all of these traits.
He only talked about correlation, not causation. The most likely causation is indeed the one you posited.
EDIT: ignore the following.
But two things that are both (positively) correlated with a third are (positively) correlated with each other, no matter the the direction or even existence of causal relations.
But two things that are both (positively) correlated with a third are (positively) correlated with each other, no matter the the direction or even existence of causal relations.
I don’t believe this is the case. Two things things both being positively correlated with a third are more likely to be correlated with each other, all things being equal. Yet there are causal relations which could make those things negatively correlated with each other while both positively correlated with the third. The most obvious examples would be of partisan behaviors where the ‘third’ is a generic factor that encourages someone to pick a side.
I don’t think “are generally” applies “no matter the the direction or even existence of causal relations”.
If A causes E and B independently causes E, then there will be correlation between A and E and between B and E, but no reason to expect correlation between A and B.
You’re right, and I really should have known better. This is one of the examples used in Judea Pearl’s Casaulity, about how to assign plausible causation structures given only correlations.
That is a surprising mistake to make in reasoning. Did you somehow get the causality arrows reversed in your mind when writing this? Temporarily imagine that fitness was causing brains and beauty, rather than the other way around?
Quite possibly true. But surely not for the reason you suggested above.
Isn’t beauty a set of built-in fitness testing heuristics? If so, fitness really does cause beauty.
It’s worth pointing out that beauty also really does cause fitness. The runaway cycle is the peacock effect.
As far as I can tell, beauty is a combination of health heuristics and status markers which are developed in particular societies—some of the status markers are about rarity and others are about costly signals.
Also known as Fisherian Runaway.
Evolution’s Goodhart Law.. Man, there is just no escaping it, is there?
By “fitness” I meant “health”.
There are no causality arrows in my reasoning.
Perhaps you think that by “fitness” I meant evolutionary fitness, and that both beauty and intelligence cause fitness. But by “fitness” I meant health. Sorry, poor choice of words.
Fitness meaning health. That works. But I think that your model does involve causality—from health to both beauty and intelligence. And, of course then beauty and intelligence will be correlated. I apologize for not anticipating that possible meaning. Since you post about evolutionary theory so often, that denotation of “fitness” never entered my mind.
Say X and Y are two independent random variables. X is correlated to X+Y is correlated to Y, but X and Y are (by hypothesis!) not correlated.
With correlations it isn’t necessarily clear which way the causality arrows are pointing—or even if they run between the correlated items at all. In this case, one of the most obvious way to draw the arrows is from genes to all of these traits.
He only talked about correlation, not causation. The most likely causation is indeed the one you posited.
EDIT: ignore the following.
But two things that are both (positively) correlated with a third are (positively) correlated with each other, no matter the the direction or even existence of causal relations.
I don’t believe this is the case. Two things things both being positively correlated with a third are more likely to be correlated with each other, all things being equal. Yet there are causal relations which could make those things negatively correlated with each other while both positively correlated with the third. The most obvious examples would be of partisan behaviors where the ‘third’ is a generic factor that encourages someone to pick a side.
You’re right. I should have said “are generally”, rather “are”.
I don’t think “are generally” applies “no matter the the direction or even existence of causal relations”.
If A causes E and B independently causes E, then there will be correlation between A and E and between B and E, but no reason to expect correlation between A and B.
You’re right, and I really should have known better. This is one of the examples used in Judea Pearl’s Casaulity, about how to assign plausible causation structures given only correlations.
A pair of correlations between A and B, and between B and C, is correlated with a correlation between A and C. :P