(2018-07-31, 05:02 PM)Chris Wrote: The blog post and comments point to several potential flaws in the experimental design:
(1) The photos included pictures of young people from old school yearbooks, and more recent photos of older people. So there was a correlation between the age of the people depicted and how recently the photos had been taken.
(2) The school yearbooks came from two quite different periods, c. 1940 and c. 1966, so there could be clues to the period from the style of clothes and hair.
...
Actually, the retracted paper does mention in the results section that "all databases contained the same number of living and deceased individuals" (though that doesn't seem to be explained clearly in the methods section). There were three databases - one from the older school yearbooks, another from the more recent ones, and the third from the photos of older people. So in that case the clues to the age of the photos shouldn't have helped.