If you have a broad enough cultural background, eye color is not a simple discrete trait either.
I was eavesdropping on the conversation behind me on the bus today:
"What color would you describe your eyes as?" a guy asks.
"Green-ish. Something like that," a girl answers.
"Good, you didn't say hazel. A bunch of people would've called them that."
And then followed a whole long discussion about how you can basically perform hierarchical agglomerative clustering on humanity's words for colors, if you follow the words linguistically back through a few thousand years. Apparently the first split happened between light & dark, and then broad colors like "blue/green" (as a single color) split off, and then modern languages broke blue & green into separate colors.
Some folks break them down even further, into "cerulean" and "turquoise" and "aquamarine" and "royal blue". I've heard (from sources other than the bus conversation) that women actually have significantly more color words in their vocabulary than men do; they make distinctions where men don't.
So eye color is a shorthand too. Some people just say "light" or "dark". Others say "brown" or "blue". Still others will break it down into "black", "brown", "blue", "green", and "hazel". Once in a while you'll get a poetic type who'll say "Eyes the color of a roiling sea, as you catch the last glimpse of sunlight before a storm rolls in."
Bringing it back on topic, intelligence is a shorthand as well. It stands for a bunch of directly observable characteristics, but which characteristics vary depending on who you ask. Some people think an intelligent person is one with a high IQ who always does well on standardized tests. Others think it's someone who accomplishes great things in the intellectual realm, another Tesla or Einstein. Still others define it as a talent, and claim there're multiple intelligences, each in one desirable realm.
Perhaps the meta-lesson isn't about race or eye color or heritability at all, it's to drill down and ask what we actually mean by such broad characteristics. When you make a statement such as "IQ has a heritability of 0.8", you're making a very specific statistical assertion (though even that's not ironclad: which IQ test?). But whether that lines up with the statement of "Intelligence is largely genetic" depends on what you mean by "intelligence" and "genetic", both of which are very broad concepts that hide a lot of subtlety.
On intelligence being a shorthand, I would add that some people define it as having an extremely good memory.
There are many people with an extreme capacity for memorizing facts and images. It is said that one of our national poets, Eminescu, wasn't able to forget anything.
By this classification, many people are and were smarter than Einstein, who apparently couldn't remember his son's or wife's birthday, or know how many feet are in a mile (although this may be just folklore). Einstein also started to speak a lot later than normal kids, at 3 years old by his own testimony and performed badly in his first years of elementary school, with his parents being warned that he had a mental disability.
And yet he was able to come up with the relativity theory, which goes to show that intelligence is indeed relative.
> On intelligence being a shorthand, I would add that some people define it as having an extremely good memory.
That's the old popular definition of intelligence, the "walking encyclopedia" model. But books, and more recently computers, have greatly reduced the value of that kind of intelligence, by being better at it than any person.
Now that we have more facts at our fingertips than we can possibly absorb, a different kind of intelligence is (a) more valuable, and (b) more likely to arise from the interaction between a human and an inexhaustible source of facts (like a computer) -- the ability to synthesize new ideas out of old ones.
In olden times, simply being able to recite facts was prized, but books and computers can now do that more efficiently -- consider that a computer recently prevailed in "Jeopardy" against a selection of very good human contestants.
The new indicator of intelligence is the ability to come to an original conclusion based on a mass of accumulated facts. Because fact collecting is more easily done by a computer, and because of the value of the ability to create new ideas out of old ones, this new meaning for intelligence may well become dominant by way of natural selection.
Here's an example I heard recently while reading about planetary science:
1. Jupiter's moon Io has volcanoes, but it's too small for those volcanoes to have the same cause as those here (Io has long since lost the heat arising from its original formation). This means that many people were able to describe Io's volcanoes, but no one could explain them.
2. Io also has an elliptical orbit around Jupiter -- which means it moves closer to, then farther from, Jupiter, during each orbit.
Someone put facts (1) and (2) together and realized that it was Io's elliptical orbit, and the consequent huge flexure of tidal force within Io's solid mass, that's heating the moon and providing the energy source for the volcanoes.
It is this kind of intelligence that is recognized -- prized -- in the present and future: the ability to synthesize.
I was eavesdropping on the conversation behind me on the bus today:
"What color would you describe your eyes as?" a guy asks.
"Green-ish. Something like that," a girl answers.
"Good, you didn't say hazel. A bunch of people would've called them that."
And then followed a whole long discussion about how you can basically perform hierarchical agglomerative clustering on humanity's words for colors, if you follow the words linguistically back through a few thousand years. Apparently the first split happened between light & dark, and then broad colors like "blue/green" (as a single color) split off, and then modern languages broke blue & green into separate colors.
Some folks break them down even further, into "cerulean" and "turquoise" and "aquamarine" and "royal blue". I've heard (from sources other than the bus conversation) that women actually have significantly more color words in their vocabulary than men do; they make distinctions where men don't.
So eye color is a shorthand too. Some people just say "light" or "dark". Others say "brown" or "blue". Still others will break it down into "black", "brown", "blue", "green", and "hazel". Once in a while you'll get a poetic type who'll say "Eyes the color of a roiling sea, as you catch the last glimpse of sunlight before a storm rolls in."
Bringing it back on topic, intelligence is a shorthand as well. It stands for a bunch of directly observable characteristics, but which characteristics vary depending on who you ask. Some people think an intelligent person is one with a high IQ who always does well on standardized tests. Others think it's someone who accomplishes great things in the intellectual realm, another Tesla or Einstein. Still others define it as a talent, and claim there're multiple intelligences, each in one desirable realm.
Perhaps the meta-lesson isn't about race or eye color or heritability at all, it's to drill down and ask what we actually mean by such broad characteristics. When you make a statement such as "IQ has a heritability of 0.8", you're making a very specific statistical assertion (though even that's not ironclad: which IQ test?). But whether that lines up with the statement of "Intelligence is largely genetic" depends on what you mean by "intelligence" and "genetic", both of which are very broad concepts that hide a lot of subtlety.