Intelligence is a better predictor for success than wealth https://www.sciencedaily.com/releases/2012/03/120329142035.h...
See The Neuroscience of Intelligence by Richard Haier for an overview of the current consensus in intelligence research.
70-80% comes from where? Nobody knows exactly what the "smart genes" are, and studies in twins show that variance between individuals in IQ is about 50%-60% genetic...or 40-50% environmental factors2A/2B
Even Haier has said that the fact that intelligence is in some way genetic just means that the factors that might influence those aspects of it would also need to be genetic. This can include things like nutrition and mental illness/stress, which are more prevalent among poorer communities.
TL;dr- Just because it's genetic, doesn't mean that it's determined at birth. Your biochemistry is constantly changing based on your environment. 1- http://www.theneuroethicsblog.com/2013/09/intelligence-testi... 2A- http://www.sciencemag.org/news/2014/10/genes-dont-just-influ... 2B*- https://ghr.nlm.nih.gov/primer/traits/intelligence
Mostly from twin studies. This number (at least the ballpark figure) is essentially uncontested amongst researchers at this point (see e.g. [1]). However, this is the heritability of the variability of intelligence in adults. In children, that number is close to the one you cited. The rest of what you’ve said is essentially true: heritability is extremely complex and we’re only now getting the first few association studies in to ascertain which genomic loci are associated with changes [2].
[1] https://www.ncbi.nlm.nih.gov/pubmed/25985137 [2] https://www.nature.com/articles/s41380-018-0040-6
But it is well established that parents’ wealth is an extremely good predictor of children’s wealth (see e.g. [1]). And I don’t think OP is matte_black is denying the role of intelligence. They’re merely noting that poverty, in itself, doesn’t necessarily correlate with ingenuity.
[1] https://paperpile.com/app/p/5f560e7d-74f8-0316-879a-70c0cf60...
But it’s not the relative importance of one thing vs the other which is most important.
What is most important in the context of this conversation, imho, is the case for the profound negative effects of poverty, United-States style, on an individuals growth and the (sometimes insurmountable) challenges it creates for that person.
And the reason that this matters is that poverty in a country such as the U.S. (and also many, if not most other countries) is the result of a series of political choices by people (social policy, etc) over time.
In over words, it’s a phenomenon which is, if not created entirely by, is definitely affected (increased or decreases) by human behavior.
Meaning it’s something we can change.
So just because parent's wealth predicts children's wealth doesn't in any way make it impossible that intelligence predicts wealth too or that they'd necessarily be in conflict.