Thank you, and I must acknowledge that listening to Dennis Prager helped me coalesce these points. Credit where credit is due, y’know!
There exists the likelihood that both environment and genetics are at play for some parts of what is considered IQ. For example, perhaps those with whatever is measurable IQ that is higher are more inclined to read more, expose their children to better environments that encourages thought growth and appeals to their natural interests thereby creating an opportunity for optimal mental performance.