Researchers should also know they're comparing iq tests and chess, which are 'single player', to 'multiplayer' games... and they even put that in their title.
I would pretty much take any "research" involving video games with a grain of salt and not be so quick to using it to make my point.
And not just involving video games, based on the history of the bad rep that was given from the first studies. Basically any study nowadays can be extremely flawed, if you dissect it and find their tester database, their ranges and parameters. Look at the food industry, you have studies that contradict themselves from one year to the next. Wine is bad, wine is good. Chocolate is bad, chocolate is good! Eggs are good, eggs are bad, eggs are good again. Etc.
In this case, like I said, it can be easily dismissed pairing the title, MULTIplayer, with the 2nd paragraph, IQ test. Not saying it's the opposite, and idiots are challenger. Surely there are correlations, and some strategies from SP can be applied to MP. Just saying it's flawed and more, in fact NEW, data is needed, to see the big picture, the entire array of vid game types.
Ha.
Moving on.