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Online tests suggest IQ scores in US dropped for the first time in nearly a century

Online tests suggest IQ scores in US dropped for the first time in nearly a century
Trends of 35-item composite ICAR scores stratified by education. Note. Data collection for the category "currently in graduate or professional school" did not start until August 2010. The dashed lines in the top graph connect the average standardized score and its associated standard error for each year and level of education. The solid lines in the top graph represent the associated slope of the average standardized score for each level of education. The lines in the bottom graph are the associated slope of the average standardized score for each level of education split between male (left) and female (right) participants. ICAR = International Cognitive Ability Resource, Grad/prof grad = Graduate or professional degree, In grad/prof = Currently in graduate or professional school, College grad = College graduate, Some college = Some college, did not graduate, In college = Currently attending college, HS = High school graduate, <12 years = <12 years of education. Credit: Intelligence (2023). DOI: 10.1016/j.intell.2023.101734

A group of psychologists, two from Northwestern University and the third from the University of Oregon, has found via online testing that IQ scores in the U.S. may be dropping for the first time in nearly a century. In their paper published in the journal Intelligence, Elizabeth Dworak, William Revelle and David Condon describe analyzing the results of online IQ tests taken by volunteers over the years 2006 to 2018.

The Flynn effect, named after James R. Flynn, is a term first coined by Richard Herrnstein and Charles Murray in 1994, in their book "The Bell Curve." In short, the effect suggests that the human race grows smarter with each successive generation—the average intelligence quotient (IQ) increases. Prior research has bolstered this theory, finding that people from successive generations have scored ever higher on IQ tests—increasing by 3 to 5 points over the years 1932 to 2000.

But more recently, it appears things have changed. Over the past several years, multiple studies have shown that IQ scores are dropping in many European countries. And now, that appears to be the case with the U.S. as well.

In this new effort, the researchers studied the results of online IQ tests taken by adults participating in the Synthetic Aperture Personality Assessment Project over a 12-year period. They found that IQ scores have dropped for all age groups, regardless of gender. They also found that the steepest declines were among . They also noted that while a few skills, such as , were better than previous generations, other skills, such as problem solving, numerical series assessments and verbal reasoning, had all grown worse.

The researchers did not conduct any research to try to explain the drop, but suggest it might be linked to changes in the education system. They also did not address the controversial issue of the accuracy of IQ test scores in general as a means of measuring a person's intelligence.

More information: Elizabeth M. Dworak et al, Looking for Flynn effects in a recent online U.S. adult sample: Examining shifts within the SAPA Project, Intelligence (2023). DOI: 10.1016/j.intell.2023.101734

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