(Phys.org) —In a new study, a European research team suggests that the average intelligence level of Victorian-era people was higher than that of modern-day people. They base their controversial assertion on reaction times (RT) to visual stimuli given as tests to people from the late 1800s to modern times—the faster the reaction time, they say, the smarter the person.
The Victorian era has been highly touted by historians as one of the most productive in human history—inventions, observations and highly acclaimed art and music from that time still resonate today. The era was defined by Queen Victoria's reign in England which ran from 1837 until her death in 1901. Comparing the average IQ of people from that time with that of modern-day people is, of course, impossible—at least using traditional methods. The researchers suggest that reaction times to stimuli can be used as an alternative way to compare relative IQ levels.
IQ tests themselves have come under scrutiny of late because they quite often reflect bias, such as education levels, societal norms, and other not-easily defined factors. Other research has shown that overall health, nutrition levels and degree of fatigue can impact IQ scores as well. For this reason, the team has turned to RT as a means of evaluating what they call general intelligence, which they claim to be a measure of elementary cognition.
The researchers didn't come up with the idea of RT as a measure of intelligence themselves; rather, they are relying on claims made by other researchers over the years that they say prove that RT is a way of measuring the "true" intelligence of a person, i.e. an intelligence measure not impacted by education level, illness, background, etc. Using such claims as a basis, the team looked at RT tests given by various researchers during the period 1884 to 2004, and found that RT rates slowly increased over the entire time period. For men, the increase was found to be 183ms to 253ms; for women the increase was from 188ms to 261ms. The researchers claim this proves that people have grown "less clever" over time. They back up their claim by suggesting they know the reason for the decline in intelligence—smarter people having fewer children, while the less smart, have more.
The claims by the European team will undoubtedly be viewed as controversial—after all, no one has proved that reaction times truly are an accurate measure of intelligence. Nor does the data suggest that those researchers testing people for their reaction times chose their subjects at random, or even in fact, performed the tests in the same way as everyone else. There's also the consideration of the Flynn effect, where other researchers have found average intelligence levels rising since the WW II.
The study has been published in the journal Intelligence.