People today are not only staying in school longer, the authors point out, but are more than ever taught to the test: Students are trained in test-taking strategies and heuristics that, according to the paper, can be applied to IQ-type problems. “People are exposed to the formats of tests all the time—they are able to detect certain regularities, and they are able to exploit those regularities,” said Michael Woodley, one of the paper’s co-authors, in an interview over Skype. “You were probably taught in school, for instance, to guess on multiple choice tests.” Even outside the classroom, increasing exposure—often online—to cognitive games like Sudoku, Bridge and Go mean that people are more familiar with IQ-type problems when they sit down to an IQ test. “We live in a more cognitively intense environment than ever,” said Woodley.
Psychology professor Dr. James Thompson praises the study:
[Co-author Elijah] Armstrong and Woodley argue that the Flynn effect is partly driven by the retest effect, whereby familiarity with the test material means that if you can learn a rule of thumb you can solve those particular sorts of problems when you see them again, without having to use much intelligence. In very simple terms, the test wears out quickly once you get to learn how it works. Using implicit learning and working memory, test takers learn how to solve rule dependent problems, which leads to apparent IQ gains which are partly independent of general intelligence.