There are a few science deniers out there, but genetics is largely responsible for IQ by the time you reach adulthood. Even personality traits can be genetic. There is a gene that is very rare in the human population, but common within people convicted of violent crimes.
This has led some to speculate on gene editing for humans,
China had three scientists jailed for gene editing human babies to make super smart, super athletic babies.
There was even speculation that a future career might be helping with affirmative action for people who aren't "gene edited," as they will be less intelligent and less athletic.
We must be careful, scientists gene editing hamsters thought they would make more docile hamsters, but it made them super aggressive.
https://www.msn.com/en-us/health/med...8d397346a538da