@gNightrow IQ is the number one predictor for success in life, it's even stronger than *actual education.* IQ stacks the odds because it can apply to a ton of different things in life, unlike education which is mostly specific to one area at a time. With higher IQ many other things tend to go up (education, status, wealth, etc.) This, statistically speaking, results in people having more stable, happy lives, and lower rates of crime, addiction, etc.
IQ is heritable by at least 40% and could be as high as 80% (the exact number is unclear).
Since IQ is heritable, this means that, even in broken homes, over the generations demographics with higher IQ will outperform those with lower IQ, because as explained IQ is the number one predictor for success. So even if a demographic with higher IQ came from dysfunctional/broken homes, their chances to increase the success of their family tree as the generations go by are much greater than of people with lower IQ, even if that second demographic came from functional/healthy homes.
