jueves, 27 de noviembre de 2008

Sesgo de confirmación

Leo en Los Angeles Times:

Jonestown and 'confirmation bias'
From Jonestown to tribalism to presidential politics, individuals seek the like-minded.
By Michael Shermer November 18, 2008

On this day 30 years ago in the jungles of Guyana, Jim Jones, leader of the Peoples Temple cult, ordered the mass suicide or murder of more than 900 of his own followers by inducing them to imbibe cyanide-laced punch or by lethal injection. He had controlled nearly all information coming into the group and warned them daily that "they" (the government, imperialists, greedy capitalists, etc.) were the enemy. So when Rep. Leo Ryan and his investigative team showed up in Guyana, Jones' followers were primed to believe that "they" were coming to destroy them and had to be stopped. After the congressman and others in his party were killed, Jones told cult members that "they" would now really come down on them, and their only choice was to move on to the next stage of life (...)

But there is something deeper going on here that I think touches on cognitive processes in all of us as members of non-cult groups, such as political parties: confirmation bias. This is when we look for and find evidence to support what we already believe, and ignore or rationalize away evidence that does not. And because we are so tribal by nature, we employ confirmation bias with extra vigor when it comes to defending the groups we belong to. Republicans tend to listen to conservative talk radio, watch Fox News and read the Wall Street Journal, gathering data and noting arguments that support their political beliefs. Democrats are more likely to listen to progressive talk radio and NPR, surf liberal blogs and read the New York Times. Everyone does it.

Confirmation bias explains why so many rumors about candidates were eagerly embraced recently. On the left, commentators glommed onto false gossip about Sarah Palin's ignorance (she doesn't know that Africa is a continent) and bigotry (she tried to ban books from the public library) because liberals think that conservatives are dumb and dogmatic, and after eight years of George W. Bush's malapropisms and Palin's interview fumbles, such rumors merely confirmed what liberals already believed.

On the right, conservatives were primed to process hearsay about Barack Obama being a Muslim or Arab as true, or that his tax plan -- indistinguishable from that of most Democratic candidates in recent decades -- confirmed that he's a socialist, even while Republicans were nationalizing the financial industry and running up record debts.

Research on confirmation bias has found that when subjects are presented with evidence that contradicts their deeply held beliefs, they dismiss it as invalid, while other subjects treat the same information as valuable when it confirms what they believe. In one study, for example, subjects were shown a video of a child taking a test. One group was told that the child was from a high socioeconomic class; the other group was told that the child was from a low socioeconomic class. The subjects were asked to evaluate the academic abilities of the child based on the results of the test. The child believed to be from the high socioeconomic group was rated as above grade level, but the child believed to be from the low socioeconomic group wasrated as below grade level. Same data. Same kid. Different interpretations (...)

It is for this reason that we need to look for disconfirmatory evidence, to listen to the arguments of those with whom we disagree, to ask for constructive criticism of our beliefs, and to remember Oliver Cromwell's words to the Church of Scotland in 1650: "I beseech you, in the bowels of Christ, think it possible you may be mistaken."


Los consejos del final me parecen muy cuerdos. En general, traten de conversar e intercambiar opiniones con quien piensa distinto; traten de recoger información que contradiga o cuestione sus convicciones. Así, al final, tendrán convicciones y creencias mucho mejor fundamentadas, mucho menos estereotipadas, y serán más tolerantes. Esto debería aplicarse a todas las cosas, desde qué diarios leemos, qué noticieros vemos, qué opiniones seguimos, etc.

Foto: Jim Jones

1 comentario:

Anónimo dijo...

Cuerdos pero bien dificiles de seguir, ya que la gente es usualmente inconsciente de sus sesgos de confirmacion. Es un tema muy antiguo en psicología cognitiva y cognición social, pero como ves sigue siendo vigente.