Do you believe people are really getting smarter? Why or why not? Since the beginning of the twentieth century, IQ scores around the world have been increasing at a rate of around three points per decade, leaving intelligence researchers puzzling over whether historical gains in IQ—known as the “Flynn effect”—reflect an increase in general intelligence or something else, be it better education, better nutrition or even bigger brains. A new paper published in the journal Learning and Individual Differences (2014) may have the answer: We’re getting better at taking tests. 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. IQ tests are updated periodically. For example, the Wechsler Intelligence Scale for Children (WISC), originally developed in 1949, was updated in 1974, in 1991, and again in 2003. The revised versions are standardized based on the performance of test-takers in standardization samples. A standard score of IQ 100 is defined as the median performance of the standardization sample. Thus one way to see changes in norms over time is to conduct a study in which the same test-takers take both an old and new version of the same test. Doing so confirms IQ gains over time. Some IQ tests, for example tests used for military draftees in NATO countries in Europe, report raw scores, and those also confirm a trend of rising scores over time. The average rate of increase seems to be about three IQ points per decade in the United States, as scaled by the Wechsler tests. The increasing test performance over time appears on every major test, in every age range, at every ability level, and in every modern industrialized country, although not necessarily at the same rate as in the United States.
The increase has been continuous and roughly linear from the earliest days of testing to the present. Though the effect is most associated with IQ increases, a similar effect has been found with increases in attention and of semantic and episodic memory. Woodley and his co-author, Elijah Armstrong, ranked 14 IQ tests according to the extent to which they could be solved by applying and re-applying rules. Some tests, like Raven’s Progressive Matrices, ask test-takers to detect complex patterns—but figuring out and reapplying a few simple rules can result in a substantial boost in scores. Other tests, like vocabulary tests, depend on recalled knowledge; they cannot be solved by using rules. (Determining the rule-dependence of tests is the most subjective part of this paper.) When Armstrong and Woodley compared data on the Flynn effect for each of the 14 different IQ tests, their results were striking: The more rule-dependent a test, the more pronounced the Flynn effect—suggesting that the Flynn effect is not due to increases in general intelligence, but to a better ability to short-circuit the test by detecting and applying certain rules.
Playing Sudoku, then, probably doesn’t increase your general mental ability—but it could improve a specific, if narrow, cognitive function. Getting better at applying rules to new test questions is another skill that might not reflect general intelligence but could still have specific applications. “The gains in IQ are not meaningless,” Woodley explained. “The Flynn effect does not mean people are getting smarter, but it does reflect people developing a huge range of narrow cognitive specializations.” Q2. Which of the factors explaining the Flynn effect do you accept? In the United States between 1932 and 1978, mean IQ scores rose 13.8 points, or approximately 0.33 points each year (Flynn, 1984), and IQ scores continued to increase at least into the mid 1990s (Rowe & Rodgers, 2002). Even more striking increases in IQ scores were reported in other countries; for example, IQ scores in Great Britain surged 27 points between 1942 and 1992 (Flynn, 1999). Smaller increases were reported in numerous other countries (e.g., France, the Netherlands, and Norway) during shorter time periods (Flynn, 1987).
The Flynn effect, as it is referred to by researchers, is supported by a growing body of research that indicates that even within relatively short timeframes, mean IQ scores tend to increase (Dickens & Flynn, 2001). Furthermore, the Flynn effect is not limited to developed countries (Daley, Whaley, Sigman, Espinosa, & Neumann, 2003). Meanwhile, research has identified numerous practical problems created by the Flynn effect. For example, rising scores require intelligence tests to be restandardized, which alters the scoring of tests such as the WAIS, and changes in test norms create difficulties in assessing the mental capacity of the mentally retarded (Tomoe & Ceci, 2003) and the elderly (Verhaeghen, 2003). Moreover, the Flynn effect may undermine the current theoretical concept of intelligence or the validity of intelligence tests (Flynn, 1984). Although numerous explanations for the Flynn effect were proposed (e.g., Dickens & Flynn, 2001; Flynn, 1987), debate on the origins of the Flynn effect continues (e.g., Rowe & Rodgers, 2002).
Most of the research on the Flynn effect was conducted in western countries (e.g., the United States, Great Britain, France, Belgium, Norway), but studies in non-Western countries indicate that the Flynn effect is not a uniquely Western phenomenon (Flynn, 1987). Between 1951 and 1975, the Japanese mean IQ score seemed to increase by approximately 20.03 points, which is more than double the increase observed in the United States during the same period (Flynn, 1987). Neither is the Flynn effect limited to developed countries; Daley et al. (2003) assessed rural Kenyan children’s performance on the most culturally neutral subscales of the WAIS between 1984 and 1988. Results indicated that scores on measures of both fluid and crystallized intelligence increases substantially during the 14-year period under study, which supports the existence of the Flynn effect in a rural area of a non-developed country (Daley et al., 2003).
The debate over the cause of the Flynn effect continues despite a growing body of research investigating its origins. Numerous theories attempt to explain the curious but important rise in IQ scores over the past centuries, but none is entirely tenable in light of current research. In the future, perhaps research will explain the Flynn effect, but at this point it seems that it is best explained by a combination of theories given that no theory can stand on its own.
There are several factors that explains the Flynn effect among them I accept few 1. Education: Students now are better educated than their ancestors, and we all that education leads to high score 2. Test talking Savvy: Today’s Children have been tested so often that they are test-savvy: they know how to take test and how to do well on them. 3. Smaller Families. In 1990, the average couple had four children; today the number is fewer than two. We know firstborns tend to have higher IQs than other children, probably because they receive more attention than their later born siblings. Q3. If the Flynn effect is true, does this undermine the theory that IQ is mostly inherited? Why or Why not?