The scientists derived their findings by analyzing data from 14 different intelligence tests conducted between 1884 and 2004 that measured the time subjects took to push a button following a stimulus, with the reaction time supposedly a measure of intelligence.
Their analysis revealed that the visual reaction times for those taking the test in the late 19th century averaged around 194 milliseconds, compared to the 275 milliseconds it took an average person in 2004 to react.
“The reduction in human intelligence (if there is any reduction) would have begun at the time that genetic selection became more relaxed,” Dr. Gerald Crabtree, professor of pathology and developmental biology at Stanford University, told The Huffington Post via email. “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’s findings counter the modern perception that intelligence, as measured by I.Q., has increased over time, a phenomenon known as the “Flynn Effect.” Dr. Jan te Nijenhuis, professor of work and organizational psychology at the University of Amsterdam and a co-author in the study, argues that this phenomenon better reflects one’s environment and education, but does not address heritable intelligence passed down from parents to children.
He also attributes the decline in intelligence to the well-documented tendency of wealthier, better-educated women to have fewer children than poorer, less-educated women.
The scientists’ findings also eerily echo the premise of the 2006 film “Idiocracy.” In the film, a man of average intelligence from the present is frozen and then unfrozen into a future world where the less-educated have vastly outbred the better-educated, ultimately resulting in a crumbling infrastructure, limited intelligence and a base culture.
Let’s hope that’s not what we should be looking forward to!
A clip from the movie “Idiocracy. We’re closer than you think!