"How do auctions do that?"

"Credits are easier to buy if you are good at your caste's work and make a lot of money at it. So talented people have more children."

"And they have talented children?"

"Talent is not perfectly hereditary but it is somewhat hereditary. They have likelier-to-be-talented children."

"How much likelier?"

"Most traits are about seventy percent heritable. That means that if you were trying to account for all of the variance between two people in that trait, seventy percent would be differences in their parents and the rest would be other factors - random chance, education, peers."

"...what is a percent of a talent?"

" - this might require more complicated math than you've learned yet in school."

"How complicated?"

"I learned it when I was four and I think most of the precursors for it were actually necessary."

"Oh. Okay."

"I will see if I can find some nice computer visualizations that let you conceptualize it."

"Thanks."

"Of course. I do think the average person in an auction country is smarter but not by a lot and averages are not everything."

"Can you check that kind of thing?"

"We do, but it's a complex subject and other factors affect intelligence and so although the evidence points towards auction countries having smarter people, it isn't strong enough yet to say for sure."

"How do you check?"

"You give everybody intelligence tests. Or, for other castes, tests for the ability we want to measure in them."

"What's the test for blues?"

"We don't actually have tests with good intertest reliability for anything other than conscientiousness, intelligence, and various physical ability measures."

"Oh. ...intertest reliability?"

"If a test is measuring something real, then it should give you about the same result if you take it several times, and two people who get the same score on one test of it should get the same score on another test of it. If your test doesn't do those, then probably it is not a very good test of the thing it's measuring, or the thing it's measuring varies too much to be meaningful. I think good judgment and decisionmaking is real and persistent, I think it's just much harder than intelligence to test." 

"I wanna take an intelligence test."

 - giggle. "Okay. I'll look up a good empirically validated one."

She does. It has lots of complete-this-pattern and analogies and draw-this-object-rotated questions.

Lintalai diligently completes patterns and does analogies and draws rotated objects.