A new study may stimulate the old adage of respecting your elders; it says the general level of intelligence in the Western Hemisphere has declined since the Victorian Era. The study claims the IQ numbers are 14 points lower than from the 19th century.
One of the authors of the study, Dr. Jan te Nijenhuis, professor of work and organizational psychology at the University of Amsterdam, says the cause of the movement toward stupidity is that smarter women have fewer children while those of lower intelligence have more children.
But Dr. Gerald Crabtree, professor of pathology and developmental biology at Stanford University, disagreed. He stated:
The reduction in human intelligence (if there is any reduction) would have begun at the time that genetic selection became more relaxed. I projected this occurred as our ancestors began to live in more supportive high density societies (cities) and had access to a steady supply of food. Both of these might have resulted from the invention of agriculture, which occurred about 5,000 to 12,000 years ago.
The study examined results of 14 intelligence studies conducted between 1884 to 2004 that measured participants' so-called visual reaction times. The test asked the participant to push a button after seeing a stimulus. In the 19th century, the average speed was 194 milliseconds, in 2004, 275 milliseconds.
te Nijenhuis dismissed studies that show a rise in I.Q. scores since the 1940s, saying that the rise was due to better education, hygiene and nutrition, and was not genetically related.