Tests to measure intelligence, like the standard IQ test from the 1940s, have largely fallen out of favor in recent decades. Researchers recognize how difficult it is to actually measure the brain’s capacity for higher reasoning and memory recall, and—as Harvard neuroscientist Howard Gardner first argued nearly 30 years ago—intelligence can come in many forms including musical and linguistic abilities.
A study published this week in the journal Neuron might just put the nail in the coffin on the standard IQ test and could pave the way for better tests to measure intelligence. Researchers from the Brain and Mind Institute in London, Ontario, had more than 100,000 volunteers complete a version of this online test that included 12 cognitive tests to assess memory, reasoning, concentration, and planning abilities, and they also performed brain scans on 16 study participants to see which circuits of the brain were activated for each of these cognitive abilities.
What they found was that variations in performance on the testing was due to differences in short-term memory, reasoning, and verbal skills. They also found that no one component—such as IQ which measures how well we reason, distinguish relationships and solve problems—explained all these variations and that distinct circuits of the brain were activated for each of the different cognitive tasks.
Interestingly, the researchers also took surveys of those who took the online test to assess their lifestyle habits and found that age was the most significant predictor of performance, with those in their 60s performing less well on memory and reasoning tests than those in their 20s.
“People who regularly played computer games did perform significantly better in terms of both reasoning and short-term memory,” study author Adrian Owen said in a statement. “And smokers performed poorly on the short-term memory and the verbal factors.” Those with high levels of anxiety also performed poorly on short-term memory tests.