From a PRI story a few years ago (“Western IQs drop by 14 points in last century, study says”):
Research published online in the journal Intelligence on Thursday claims the IQ of people in Western nations has fallen by an average of 14.1 points over the past century…
So why are we supposedly getting dumber?
Previous research has found that women of higher intelligence are having fewer children, meaning women of lower intelligence are driving population growth, according to the study.
Over time, experts say, that would affect the average IQ of a population.
A massive influx of predominately low-IQ, high-fertility, Third Word immigrants (i.e., r-selective races) into a high-IQ, k-selective society leads to this.
It’s called dysgenics, and Richard Lynn has written extensively on the subject. His book “Dysgenics: Genetic Deterioration in Modern Populations” is available for free online here.