The phenomenon whereby each successive generation of people exhibits a rise in IQ is called the Flynn Effect. This phenomenon was first observed in the late 1970s and published as a study in 1984 by James Flynn, whose name the phenomenon bears. The study revealed that IQ scores on the Stanford-Binet and Wechsler intelligence tests increased approximately 0.3 points per year over the period from 1932 to 1978, or roughly three points per decade.
Countries whose IQ test data have been evaluated as part of the Flynn Effect include Great Britain, Canada, Australia, Germany, Sweden, The Netherlands, Israel, Japan, China and several more, in addition to the United States. The effect has been observed across all of these cultures, although the outcomes vary.
See our ranking of the 10 Most Affordable Counseling Psychology Online Programs.
What IQ Tests Show
PsycholoGenie notes that IQ tests administered to people in many different cultures prove that a linear and uninterrupted increase in average human intelligence occurs with each succeeding generation. All scores were normalized to provide an average for every generation so that test results could be compared with each other. Flynn indicates that higher intelligence levels are the result of a combination of factors, such as increasing technology, that increase with each generation. The most striking example of change is the addition of the internet to daily lives. An average child today is exposed to and understands much more information at an earlier age than his or her parents did. Other factors, such as better nutrition, also play a role.
What Types of Intelligence Were Measured?
Human Intelligence notes that the Flynn Effect measures two types of intelligence: fluid intelligence and crystallized intelligence. The first measures problem solving and show an average increase of about 15 points per generation. These results are not due to educational factors. Purely verbal tests measure crystallized intelligence, and while they do measure problem solving, they also determine the level of other learned information such as math skills and vocabulary. These gains are smaller, showing an increase of about nine points per generation.
What Causes These Gains?
Scholars continue to research why intelligence keeps increasing, and Flynn himself has indicated three possible areas that provide answers. These are artifacts, including improvements in early childhood education, test sophistication and actual increases in intelligence. Flynn has also hypothesized that the measurable increases result from increases in abstract problem solving rather than an increase in intelligence.
Other possible explanations for gains in IQ levels include the increase in formal education in many countries, societal changes that prompt individuals to work better when faced with limited time frames on tests and better nutrition worldwide. The theory that brains with better nourishment allow test takers to perform better on these measurements as well as during daily functioning. Data from all of these theories, however, are mixed and are considering contributing but not overwhelming factors.
Routine Restandardization of Testing
IQ tests constantly undergo reformulation so that the subjects taking the tests are not scored against inaccurate norms. This is especially important when comparing the scores of different cultural groups.
The Flynn Effect hs also debunked the theory that people lose fluid intelligence as they age. Research on the Flynn Effect needs to continue as the subject of learned intelligence has not yet been fully explored.