Caplan’s claim doesn’t depend on this line of argumentation, but if it was true (which it’s not) it would make his point extremely strongly. Weaker claim that normal parenting styles don’t affect outcomes much, because the rest of environment (and genes) together have much greater impact is perfectly defensible.
You’re too lazy, no shortcuts this time.
Caplan’s claim doesn’t depend on this line of argumentation, but if it was true (which it’s not) it would make his point extremely strongly. Weaker claim that normal parenting styles don’t affect outcomes much, because the rest of environment (and genes) together have much greater impact is perfectly defensible.