Lecture 7 - The Flynn Effect And The Decline Of "g" Flashcards
How much was the average increase in IQ scores over the decades in the 20th century?
Equivalent to a couple of IQ points. 2-3
This means that the average score in 1950 might have been 100 and then in 1960 it was 103.
If there was an average increase in scores, what hard to happen to the tests every 10-15 years?
Had to be restandardized
List 5 reasons that might explain the Flynn effect?
1) “g” has increased
2) pre and post natal nutrition has improved which means better brain development and then also less malnutrition so concentration is better for the actual test taking
3) switch in test style from read/recall test to MCQ/recognise test. Recognition tests are easier
4) familiarity with IQ testing leads to practice effects and cheating
5) modern culture is a better preparation for this kind of test - structure of modern life with technology leads to more abstract thinking and thinking systematically (like computers)
List 6 examples of how we can measure that “g” has actually declined over the last 100 years?
1) decline in the number of geniuses and rate of major innovations
2) slowing of simple reaction times
3) reaching piagetian cognitive development stages later in childhood
4) rise in IQ scores is in the least “g” loaded subtests (Ravens matrices forward digit span) no rise and sometimes decline in the more “g” loaded subtests (vocabulary and backward digit)
5) asymmetry in skulls in the last 100 years which implies greater developmental instability which couples with mutation accumulation
6) inverse correlation of intelligence with fertility and increased probability of mutation accumulation due to decreased child mortality
5)
How does simple reaction times measure “g” what were they like in the 1800s compared to now ?
“G” is simply a measure of the efficiency of your brain and how well it processes things. Therefore reaction times is a simple processing task.
In the 1800s reaction times : 180ms
In a recent study: 250-300ms
According to the reaction time tests what would be the raw IQ scores of the Victorians be compared to now?
Approximately 1 IQ point or more has been lost per decade.
Therefore, the average now is 100 and the average Victorian would score 115.
But who did they test in the Victorian sample? Were they well nourished which increased their concentration?
Conclusion of the lecture… What can the rise in IQ raw scores and decline in general intelligence tell us about fitness indicators?
If “g” is a fitness indicator, then it’s decline shows a decrease in genetic quality. But the increase in scores tells us that there are softer / improved social conditions
What is the broad definition of the Flynn effect?
Through the 20th century there was a general increase in the raw scores of IQ tests on average in the western countries
