There are four variables of interest in a statistical power analysis: power (often chosen as 0.8 or 0.9 by convention, this is the probability of correctly rejecting the null hypothesis if it is false), tolerated false-positive rate (alpha, often chosen as 0.05 by convention), sample size, and the effect size (which in turn depends on the variability of the ...
It seems that specifics on the heredity of IQ are largely unknown today. That same wiki page says,
Intelligence in the normal range is a polygenic trait, meaning that it is influenced by more than one gene, and in the case of intelligence at least 500 genes.
The frequency and disconnection of studies like this and this shows just how uncertain this field ...
Attempting to reduce emotional responses to mathematics is likely in the realm of chaos theory.
Here is a great Robert Sapolsky Stanford lecture on Chaos versus Reductionism.