You're claiming this study used a test that it could have a "the test result" for, but it didn't - it's a meta analysis using another meta analysis, whose different studies all used different tests:
> We contacted investigators for all eight prospective lead cohorts that were initiated before 1995, and we were able to retrieve data sets and collaboration from seven. The participating sites were Boston (Bellinger et al. 1992); Cincinnati (Dietrich et al. 1993) and Cleveland, Ohio (Ernhart et al. 1989); Mexico City, Mexico (Schnaas et al. 2000); Port Pirie, Australia (Baghurst et al. 1992); Rochester, New York (Canfield et al. 2003); and Yugoslavia (Wasserman et al. 1997).
> We measured blood lead concentrations in 172 children at 6, 12, 18, 24, 36, 48, and 60 months of age and administered the Stanford–Binet Intelligence Scale at the ages of 3 and 5 years.
So they didn't all take the same test[0]. This supports my claim, which is that people who believe IQ research also believe that all test results produce the same valid statistic called IQ as long as the test calls itself an IQ test.
I actually can't think of a time I've seen an online IQ arguer claim that any given test result isn't an accurate representation of an IQ. They certainly also think it about things like SAT scores and old national-IQ studies where they gave the tests in second/third languages or just made up the numbers.
[0] if it was the same test, isn't the norm process to convert from raw scores to normally distributed ones be different in different years? Not sure how that part is done.
https://www.thelancet.com/journals/lanplh/article/PIIS2542-5... <- the one in the article
https://ehp.niehs.nih.gov/doi/10.1289/ehp.7688 <- the one it refers to
> We contacted investigators for all eight prospective lead cohorts that were initiated before 1995, and we were able to retrieve data sets and collaboration from seven. The participating sites were Boston (Bellinger et al. 1992); Cincinnati (Dietrich et al. 1993) and Cleveland, Ohio (Ernhart et al. 1989); Mexico City, Mexico (Schnaas et al. 2000); Port Pirie, Australia (Baghurst et al. 1992); Rochester, New York (Canfield et al. 2003); and Yugoslavia (Wasserman et al. 1997).
I checked two of the studies from 1989:
https://www.sciencedirect.com/science/article/abs/pii/089203...
> The test used was the Wechsler Preschool and Primary Scale of Intelligence.
https://www.nejm.org/doi/full/10.1056/NEJMoa022848
> We measured blood lead concentrations in 172 children at 6, 12, 18, 24, 36, 48, and 60 months of age and administered the Stanford–Binet Intelligence Scale at the ages of 3 and 5 years.
So they didn't all take the same test[0]. This supports my claim, which is that people who believe IQ research also believe that all test results produce the same valid statistic called IQ as long as the test calls itself an IQ test.
I actually can't think of a time I've seen an online IQ arguer claim that any given test result isn't an accurate representation of an IQ. They certainly also think it about things like SAT scores and old national-IQ studies where they gave the tests in second/third languages or just made up the numbers.
[0] if it was the same test, isn't the norm process to convert from raw scores to normally distributed ones be different in different years? Not sure how that part is done.