I think you're mixing your science, but in any event it sounds like you and the author of this article have a lot to discuss...
Quote:
The notion that intelligence across the world may be in decline was first inferred by Lentz (1927) in the U.S., who made an observation that intelligent couples were having fewer kids than those with average intelligence. This conjecture has been confirmed by studies like that of Hernstein and Murray (1994), who demonstrated that in the U.S. females with an average IQ of 111 had 1.6 children, whereas females with an average IQ of 81 had 2.6 children.
The link between high IQ and fewer kids is known as dysgenic fertility.
Because intelligence to an extent is heritable, it was postulated that intelligence across the world may be in decline. When empirical studies measuring intelligence of people across the world were conducted it was discovered that intelligence across the world was actually rising. This phenomenon is now known as the Flynn effect due to extensive work done by Flynn (1984) in confirming the aforementioned phenomena.
Look at the disclaimer in the text you quote.
Point is these are people that make a living off of a hypothesis which translates into a lifetime of grants.
Intelligence is to a degree inheritable.
Intelligence is balanced within society, so less can give rise to more.
Intelligence, more specifically our big brains, are developed by repetition. Activities can be performed to increase over the generations "IQ."
IQ is overrated as the be all and end all of intelligence. Most modern experts accept the multi facet aspect of genius.
The blind spot in the so called science is the cultural and normative bias, that is inevitably applied.