CASE INCIDENT 1
Given that a substantial amount of intellectual ability is inherited, it might surprise you to learn that intelligence test scores are rising. In fact, scores have risen so dramatically that today's great-grandparents seem mentally deficient by comparison. First, let's review the evidence for rising test scores. Then we'll review explanations for the results. On an IQ scale where 100 is the average, scores have been rising about 3 points per decade, meaning if your grandparent scored 100, the average score for your generation would be around 115. That's a pretty big difference-about a standard deviation, meaning someone from your grandparent's generation whose score was at the 84th percentile would be only average (50th percentile) by today's norms. James Flynn is a New Zealand researcher credited with first documenting the rising scores. He reported the results in 1984, when he found that almost everyone who took a well-validated IQ test in the 1970s did better than those who took one in the 1940s. The results appear to hold up across cultures. Test scores are rising not only in the United States but in most other countries in which the effect has been tested, too. What explains the Flynn effect?
Researchers are not entirely sure, but some of the explanations offered are these:
1. Education. Students today are better educated than their ancestors, and education leads to higher test scores.
2. Smaller families. In 1900, 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.
3. Test-taking savvy. Today's children have been tested so often that they are test-savvy: they know how to take tests and how to do well on them.
4. Genes. Although smart couples tend to have fewer, not more, children (which might lead us to expect intelligence in the population to drop over time), it's possible that due to better education, tracking, and testing, those who do have the right genes are better able to exploit those advantages. Some genetics researchers also have argued that if genes for intelligence carried by both parents are dominant, they win out, meaning the child's IQ will be as high as or higher than those of the parents. Despite the strong heritability of IQ, researchers continue to pursue mechanisms that might raise IQ scores. Factors like brain exercises (even video games) and regular physical exercise seem to at least temporarily boost brain power. Other recent research in neuroscience has had difficulty pinpointing physical mechanisms that can lead to a boost in IQ, although researchers propose that a focus on brain chemicals like dopamine may lead, in time, to drugs that can boost IQ chemically.
Questions
1. Do you believe people are really getting smarter? Why or why not?
2. Which of the factors explaining the Flynn effect do you accept?
3. If the Flynn effect is true, does this undermine the theory that IQ is mostly inherited? Why or why not?