Is Multitasking Making Us Less Smart?
Science reveals that multitasking ability and IQ may be linked.
Posted March 2, 2018 | Reviewed by Gary Drevitch
I love strange scientific studies. The fascination started with a research paper from the University of Cambridge in which scientists discovered that howler monkeys with smaller testes have larger vocal tracts. In other words, less “equipped” monkeys tend to compensate with increased volume. More than once I’ve shared this fact at parties with particularly obnoxious or drunk individuals. Fortunately, I haven’t been punched yet.
So, you can imagine how thrilled I was to discover a paper which compared cell phone use and cannabis. According to the internet, one study by the University of London found that multitasking regularly, like checking your phone at meetings, is more harmful to IQ than smoking cannabis, and may even cause brain damage. Sadly, however, the more I searched for the actual cite, the clearer it became that this was not the actual finding. Like many other people, I had been duped while seeking distractions from my actual work.
Yet, there is extensive research on multitasking, and it’s not as dire as you think. The actual study by the University of London did look at IQ changes with multitasking, but found that it hardly affected female employees at all. For men it lowered IQ by about 10 points, but only during the distractions and not necessarily after. Granted, the sample was only eight employees hired as publicists for Hewlett Packard, but it was a start.
Other work has shown more permanent links between intelligence and multitasking, but not in a negative way. Mary Courage from Memorial University in Newfoundland has shown that multitasking may not have a negative impact on children’s attentional capacity after all, and may even have benefits when managed properly. Although performance on complex tasks is almost always worse when attention is divided, with practice and use of appropriate strategies, the loss from multitasking can be minimal. Granted, for some actions like driving a car, no amount of practice will make multitasking safe, but if your job is straightforward, you’re probably okay checking your phone now and then.
One reason that multitasking might not be as bad as we thought is that our brains change with training, and practice controlling our attention makes us better. One study from the University of Madrid found that multitasking ability shares a close relationship with both working memory capacity and intelligence, suggesting that they share common neural mechanisms. When that relationship was further teased apart, they found that this shared relationship was due mostly to memory ability. In other words, our ability to hold and use information for short periods of time affects nearly everything we do. It tells us how well we’ll manage those competing phone calls and emails. It even says a lot about our IQ score.
Still, multitasking has its costs: Stanford researchers have found that heavy media multitaskers — those who regularly check multiple news and entertainment sources at once — actually perform worse at switching between tasks. This was particularly surprising, as these are the individuals with the most practice switching. Other research shows that these same individuals have less-developed anterior cingula, the part of the brain responsible for managing our attention. In other words, when we’re used to taking in information from many places at once, we lose some ability to shift our attention when we need to.
So, what is the verdict on multitasking? One recommendation is to control the information you receive, because more isn’t always better. That’s different than saying we shouldn’t multitask, however. Sometimes we need to do multiple things at once. Practice might even help, but if you’re overwhelmed then you’re probably doing everything poorly. In cases like that, if you’re a howler monkey it’s best just to yell.
And if you’re a howler monkey with particularly small testes, yell loud. Very loud.
Courage, M., Bakhtiar, A., Fitzpatrick, C., Kenny, S., and Brandeau, K. (2015). Growing up multitasking: The costs and benefits for cognitive development, Developmental Review, 35, 5-41.
Colom, R., Martinez-Molina, A., Shih, P., and Santacreu, J. (2010). Intelligence, working memory, and multitasking, Intelligence, 38, 543-551.
Loh, K. and Kanai, R. (2014). Higher Media MultiTasking Activity Is Associated with Smaller Gray-Matter Density in the Anterior Cingulate Cortex, PLoS One, 9, 1-7.
Ophir, E., Nass, C., and Wagner, A. (2009). Cognitive Control in Media Multitaskers, PNAS, 106, 15583-15587.