The Bell Curve (1994) argued that the average genotypic IQ of the United States was declining due to both dysgenetic fertility and large scale immigration of groups with low average IQ.
Few people know that the average IQ of Americana has been going lower over the last fifty years or so. And, this was planned. People with lower IQ's are easier to manipulate. The ruling 1%, that the Liberals hate so much, are actually planning to control populations to the point of taking their freedoms away. But like the small child that can be convinced to get into a stranger's car for a piece of candy, the Liberals are following along and not realizing the people they are following, are leading them over the cliff.
Yes, IQ IS inherited. That debate is over. If humans were smart, they would reproduce for other reasons than good looks or body type. They would want more for their children than good looks or a good body. People with lower IQ's have a much harder life. This leads to depression, drug use, alcoholism and suicide. Not that this group are the only ones that have these problems, just that they are more likely to have them.
Consider the lower grade averages of the children these days. The tendency to follow stupid trends and fads. The lack of independent thinking. The desire to stay a child and live with one's parents long after adulthood. These are all signs of a population whose IQ has lowered to the point of endangering the human race.
If it isn't turned around, and soon, humans might not make it another 500 years.