The Filter Bubble - Eli Pariser [34]
Once we’ve acquired schemata, we’re predisposed to strengthen them. Psychological researchers call this confirmation bias—a tendency to believe things that reinforce our existing views, to see what we want to see.
One of the first and best studies of confirmation bias comes from the end of the college football season in 1951—Princeton versus Dartmouth. Princeton hadn’t lost a game all season. Its quarterback, Dick Kazmaier, had just been on the cover of Time. Things started off pretty rough, but after Kazmaier was sent off the field in the second quarter with a broken nose, the game got really dirty. In the ensuing melee, a Dartmouth player ended up with a broken leg.
Princeton won, but afterward there were recriminations in both college’s papers. Princetonians blamed Dartmouth for starting the low blows; Dartmouth thought Princeton had an ax to grind once their quarterback got hurt. Luckily, there were some psychologists on hand to make sense of the conflicting versions of events.
They asked groups of students from both schools who hadn’t seen the game to watch a film of it and count how many infractions each side made. Princeton students, on average, saw 9.8 infractions by Dartmouth; Dartmouth students thought their team was guilty of only 4.3. One Dartmouth alumnus who received a copy of the film complained that his version must be missing parts—he didn’t see any of the roughhousing he’d heard about. Boosters of each school saw what they wanted to see, not what was actually on the film.
Philip Tetlock, a political scientist, found similar results when he invited a variety of academics and pundits into his office and asked them to make predictions about the future in their areas of expertise. Would the Soviet Union fall in the next ten years? In what year would the U.S. economy start growing again? For ten years, Tetlock kept asking these questions. He asked them not only of experts, but also of folks he’d brought in off the street—plumbers and schoolteachers with no special expertise in politics or history. When he finally compiled the results, even he was surprised. It wasn’t just that the normal folks’ predictions beat the experts’. The experts’ predictions weren’t even close.
Why? Experts have a lot invested in the theories they’ve developed to explain the world. And after a few years of working on them, they tend to see them everywhere. For example, bullish stock analysts banking on rosy financial scenarios were unable to identify the housing bubble that nearly bankrupted the economy—even though the trends that drove it were pretty clear to anyone looking. It’s not just that experts are vulnerable to confirmation bias—it’s that they’re especially vulnerable to it.
No schema is an island: Ideas in our heads are connected in networks and hierarchies. Key isn’t a useful concept without lock, door, and a slew of other supporting ideas. If we change these concepts too quickly—altering our concept of door without adjusting lock, for example—we could end up removing or altering ideas that other ideas depend on and have the whole system come crashing down. Confirmation bias is a conservative mental force helping to shore up our schemata against erosion.
Learning, then, is a balance. Jean Piaget, one of the major figures in developmental psychology, describes it as a process of assimilation and accommodation. Assimilation happens when children adapt objects to their existing cognitive structures—as when an infant identifies every object placed in the crib as something to suck on. Accommodation happens when we adjust our schemata to new information—“Ah, this isn’t something to suck on, it’s something to make