Jordan Peterson on psychology: what the evidence says · JRE #1769
SUBJECT: PSYCHOLOGY
Not a true/false call. Every claim is logged with its sources; read the exhibits below.
one of the things that's happened over the last century is the mean IQ has gone up seven points per generation, which is a lot, like it's really a lot. So 15 point IQ difference is the average difference between the typical high school graduate and the typical college graduate.
What the evidence says 01 / RECORD
Peterson describes a real phenomenon, the Flynn effect, the well-documented rise in raw IQ test scores across the 20th century, but overstates its size. Formal meta-analyses put the average gain at roughly three to three-and-a-half IQ points per decade (about 4.5 to 5 points per 15-year generation), not the seven points per generation Peterson states, a figure roughly 1.5 to 2 times the documented pace. Research since the 1980s and 1990s also shows the effect has stalled or reversed in several developed countries, including Scandinavia and, more recently, some U.S. samples, meaning the century-long rise Peterson describes is not uniform through to the present. His secondary claim, that this equals roughly half the IQ gap between a typical high school graduate and college graduate, is a rough approximation rather than a formally established statistic. Overall status: misleading, real underlying effect, magnitude and framing exaggerated.