Early on a drab afternoon in January, a dozen third graders from the working-class suburb of Chicago Heights, Ill., burst into the Mac Lab on the ground floor of Washington-McKinley School in a blur of blue pants, blue vests and white shirts. Minutes later, they were hunkered down in front of the Apple computers lining the room’s perimeter, hoping to do what was, until recently, considered impossible: increase their intelligence through training.
“Can somebody raise their hand,” asked Kate Wulfson, the instructor, “and explain to me how you get points?”
On each of the children’s monitors, there was a cartoon image of a haunted house, with bats and a crescent moon in a midnight blue sky. Every few seconds, a black cat appeared in one of the house’s five windows, then vanished. The exercise was divided into levels. On Level 1, the children earned a point by remembering which window the cat was just in. Easy. But the game is progressive: the cats keep coming, and the kids have to keep watching and remembering.
“And here’s where it gets confusing,” Wulfson continued. “If you get to Level 2, you have to remember where the cat was two windows ago. The time before last. For Level 3, you have to remember where it was three times ago. Level 4 is four times ago. That’s hard. You have to keep track. O.K., ready? Once we start, anyone who talks loses a star.”
So began 10 minutes of a remarkably demanding concentration game. At Level 2, even adults find the task somewhat taxing. Almost no one gets past Level 3 without training. But most people who stick with the game do get better with practice. This isn’t surprising: practice improves performance on almost every task humans engage in, whether it’s learning to read or playing horseshoes.
What is surprising is what else it improved. In a 2008 study, Susanne Jaeggi and Martin Buschkuehl, now of the University of Maryland, found that young adults who practiced a stripped-down, less cartoonish version of the game also showed improvement in a fundamental cognitive ability known as “fluid” intelligence: the capacity to solve novel problems, to learn, to reason, to see connections and to get to the bottom of things. The implication was that playing the game literally makes people smarter.
Psychologists have long regarded intelligence as coming in two flavors: crystallized intelligence, the treasure trove of stored-up information and how-to knowledge (the sort of thing tested on “Jeopardy!” or put to use when you ride a bicycle); and fluid intelligence. Crystallized intelligence grows as you age; fluid intelligence has long been known to peak in early adulthood, around college age, and then to decline gradually. And unlike physical conditioning, which can transform 98-pound weaklings into hunks, fluid intelligence has always been considered impervious to training.
That, after all, is the premise of I.Q. tests, or at least the portion that measures fluid intelligence: we can test you now and predict all sorts of things in the future, because fluid intelligence supposedly sets in early and is fairly immutable. While parents, teachers and others play an essential role in establishing an environment in which a child’s intellect can grow, even Tiger Mothers generally expect only higher grades will come from their children’s diligence — not better brains.
How, then, could watching black cats in a haunted house possibly increase something as profound as fluid intelligence? Because the deceptively simple game, it turns out, targets the most elemental of cognitive skills: “working” memory. What long-term memory is to crystallized intelligence, working memory is to fluid intelligence. Working memory is more than just the ability to remember a telephone number long enough to dial it; it’s the capacity to manipulate the information you’re holding in your head — to add or subtract those numbers, place them in reverse order or sort them from high to low. Understanding a metaphor or an analogy is equally dependent on working memory; you can’t follow even a simple statement like “See Jane run” if you can’t put together how “see” and “Jane” connect with “run.” Without it, you can’t make sense of anything.