@TuringEquivalent,
I'm about halfway in and have already spotted simplistic statements like:
"Two people raised in the same house by the same parents have 100% the same environment."
That is obviously wrong for a couple reasons. First, if the siblings differ by a couple years in age, then one has the experience of of growing up with an older sibling, while the other has the experience of growing up with a younger sibling. Totally different, in other words. Second, even if you're talking about fraternal twins, one may be an early bloomer, and the other a late bloomer. So again you effectively give one a more-mature, dominant sibling to work with, while you give the other a less-mature sibling. It's a key environmental difference in what they will be exposed to.
Of course, it's hard to have "powerful" models unless you abstract out half the important facts.
So far, I needn't even quibble about your analysis. I flat out disagree with the lecture.
In any case, I already knew about the heritability of IQ. That personality differences could be innate as well seems like the most interesting point.